New Samsung smartphones running Android Oreo (Galaxy S, Galaxy Note and A series) have a new icon that looks like a triangle with arrows inside.
This feature is also called “data saving”
A triangle icon with two arrows inside appears in line with the battery indicator in the notification bar.
The “triangle with arrows” icon stands for “traffic saving”. When the icon appears on the screen, it means that the traffic saving feature is active.
Most applications require the Internet to activate and work. When the device is in a Wi-Fi zone, the user does not have to worry about mobile traffic. But as soon as the smartphone leaves the free Internet zone, the waste of mobile traffic begins, and it continues even when the application is in the background. And the user may not even notice how the limit is reached. A saving function was developed specifically to save mobile traffic.
Traffic savings:
Data saving may be active by default
Instructions:
Overall, this is a useful feature that saves money and extends battery life. But if the user is in a Wi-Fi zone, there is no need for this option to work.
Lesson 3. Taskbar
At the bottom of the screen is the taskbar. Let's take a closer look at it.
As you can see, it consists of several parts. On the left is the Start button (), which brings up the Start menu of the same name (see the figure on the right). We have already reviewed the left side of this menu. The right side contains:
Alexander is the name of the user who is currently on the computer (not a mode).
Documents - calls the folder with user Alexander’s documents. If another user were on the computer, the other user's documents folder would open.
Images, Music- user Alexander’s folders with images and music. After installing Windows 7, all these folders are empty. Note that all these folders (documents, pictures and music) are located on the same disk where Windows 7 is installed and if you need to reboot this system and format the disk, the data will be destroyed. To restore data, before reinstalling the system, it is possible to save the data, which we will discuss in additional questions.
Games - contains a folder with standard games. After a window with a list of games appears, you can double-click on the game icon and it will begin to play.
Computer - call the Explorer program, the window of which contains a list of logical drives (the operation of this program will be discussed later).
Control Panel - main mode for configuring the operating system. Some modes will be discussed in lessons; a detailed description will be given in the reference section.
Devices and Printers- displays a list of connected devices to the computer, including printers.
Default programs- correspondence of files to the programs that launch them, so that when you click on a file, the corresponding program is called, setting the default browser, and so on. As a rule, the system itself configures the matching data and this mode is used quite rarely.
Help and support- call the help system.
This panel is used to call programs for execution. The question may arise - why is this panel needed if you can run the program from the desktop. There are times when several programs are running on the computer and, accordingly, several windows are located on the screen, each for its own program. In this case, the contents of the desktop are not visible, and the bottom line (taskbar) is always open to the user. In order not to remove windows from the screen in order to free up the desktop, this panel is used.
If you move the cursor to the icon on this panel, an inscription with the name of this program will appear, as shown in the figure on the right. In this example, the mouse cursor is moved to the icon of the Internet Explorer program, which works with the Internet. 
If you click on the program icon, it will be executed.
To remove an icon, you need to right-click on it. A panel will appear on the screen in which you need to select a mode Remove a program from the taskbar(see picture on the left). The top part of the panel shows the pages that have been accessed from the program recently. If this were an explorer program, there would be a list of folders that were viewed and so on.
To insert a new icon into the Quick Access Toolbar, you can drag it from the desktop (or Start menu) to the toolbar (picture on the right).
You can move the icons in the panel to change their order in the panel. To do this, you need to drag the icon to a new location in the panel. To do this, you need to move the cursor to the icon, click on the left mouse button and, without releasing it, move it to a new location. In this case, a program icon will appear near the mouse pointer, which will move along with the cursor.
The middle part of the panel is designed to show running programs. Let's assume that the Skype and CompoZer programs are called, as well as one mode (the help system). In the future, for convenience, we will also call modes programs (see the figure below).
As you can see in the middle part (to the right of the Quick Launch panel) there are three rectangles with icons. One is the Skype () program, the second is CompoZer (), the third is the Windows help system (). One of the rectangles is depressed (has a lighter background) (), which indicates that this is an active task. The other two are not depressed, which indicates their passivity. There can only be one active task on the screen. It differs from others in that its window is located on top of all windows, and all user actions using the mouse and keyboard will be carried out with this window. The second type of task execution is when calculations are performed, data is transferred, etc., but the keyboard and mouse cannot perform any actions. In order for a task to become active, you need to click either on the task window or on the rectangle in the middle part of the taskbar. If you click on the Skype rectangle (), this task will become active.
If you exit the program, the rectangle for this task will disappear from the taskbar. If you start a new program, a new rectangle will appear. How to terminate the program (or close the program) has already been written (you need to click on the buttontop right of the program window).
If you move the mouse cursor to a program icon, a smaller window of this program will appear at the top of the panel. If one program is running, then one window will appear, if more than one, then the corresponding number of windows (figure below), and at the top it will be indicated which folders the program is currently working with. This applies not only to icons on the taskbar, but also to icons on the Quick Access Toolbar.
Let's launch the Explorer program. Now let’s minimize the window of this program by clicking on the button with a dash located on the right at the top of the window (). As a result, the window will be minimized, that is, it will not be displayed on the display screen, and the button in the form of a small rectangle on which the name Explorer is located, located in the bottom line, will become released (it will become released, since there is another program on the screen that will become active ). This operation is called minimizing the window. In this case, the program will continue to perform its actions. If we downloaded a file from the Internet and minimized the window of this program, the download would still continue.
In order to expand the window with the Explorer program, you need to click on the button located in the middle part of the taskbar. In this case, the window will appear on the screen, and the button will seem to be pressed in, that is, the program will become active again.
Thus, you can minimize and maximize the program window. These actions are also called: minimize or expand a program window.
Sometimes you need to enter some text from the keyboard. This could be the name of the file, the address of the page on the Internet, etc. As a rule, after turning on the computer, you can type Cyrillic characters, that is, Russian language characters. In order to type English letters, you need to change the keyboard layout. A layout is a table of symbols that corresponds to the keyboard keys at the moment. In order to switch to the Latin alphabet (English characters) for entering them, you can use two options. First of all, we note that at the bottom left of the screen on the bottom line there is the inscription - Ru (). This means that the keyboard layout is Cyrillic, that is, when you press a key, Russian characters will be entered.
Now let's change the layout to Latin. Press the Shift key, and without releasing it, press and release the Alt key. It is necessary to press so that when you press the Alt key, the Shift key is also pressed at that time. Usually this is done within a second or two, but when you do it for the first time, it may take longer. After performing this operation, the inscription - EN () will appear on the bottom line. If you press these keys again, the inscription “Ru” will appear again and so on. 
Let's describe the second method of changing the layout. To do this, click on the inscription - Ru and a panel will appear, the appearance of which is shown in the figure on the right. If you click on EN, the layout will change to Latin (English characters). You can also switch to Russian by clicking on RU.
The notification panel displays icons for modes and programs that are currently running. Let's look at them in more detail. 
The right side of the panel shows the current time (16:31) and below the current date. If you move the cursor to these numbers, a window with the current date and day of the week will appear on the screen (see the figure on the left).
If you click on the current time, a window will appear on the screen, the view of which is shown on the right. It contains the current date and time. In order to change these parameters, click on the inscription Changing the date and time. In this case, a window will appear on the screen, the appearance of which is shown below.
Click on the button Change date and time... (picture on the right).
First of all, let's set the date. As you can see in the window there is a Date field, under which there is the name of the current month and to the right and left of it there are buttons in the form of triangles, the tips of which are directed in different directions. In order to change the name of the month towards the previous one, click on the button located to the left of the name (). In order to change the name of the month towards the next one in order, click on the button located to the right of the month name ().
Let us now move on to changing the name of the year, which we will set as follows. You need to move the cursor to the field in which the inscription September 2011 is located, click on it with the left mouse button, after which the contents of this field will change, as shown in the figure on the left. 
In this window we will set the month. Click on the year number with the left mouse button, a new window will appear on the screen (picture on the right), in which you need to select a new value. If the desired year number is not in the window, then you can, as before, use the buttons with triangles (,).
The right side of the window contains the current time value, which consists of three values: the current hour, minutes and seconds. In order to change the hour, move the cursor to the first two digits “10” and click the left mouse button. After the keyboard cursor appears as a flashing dash (), you should press the buttons with vertical up and down arrows to increase or decrease the value of the current hour (). Next, we will do the same with minutes and seconds.
To enter numbers from the keyboard, use your mouse to highlight two numbers. To do this, you need to move the cursor to the left side of the first digit, click on the left mouse button and, without releasing it, move the mouse cursor through two digits, and then release the left mouse button. As a result, two numbers will be highlighted in dark color and their values can be entered using the keyboard ().
Thus, with each icon or field you can do the following:
Move the mouse cursor to the icon;
Click on the icon with the left mouse button;
Double-click on the icon with the left mouse button;
Right-click on the icon.
This can lead to various consequences. Sometimes they lead to one result, for example, double-clicking or left-clicking once on a time value will lead to one result. But it often leads to different results.
The next icon is the volume level (). If you move the mouse cursor to this icon, a window with the volume level will appear. In this example, the volume level is 67 percent.
If you click on this icon, a window with a slider will appear above it (the window on the left). This slider () can be pulled down, the volume level will decrease, if up, it will increase. If you press the loudspeaker button (), the loudspeaker will be turned off. When pressed again, it will be turned on again.
The next icon is the network connection indicator (). You can try to see for yourself what happens if you move the cursor to this icon or click on it.
The next icon is the power connection indicator. This icon is only used on laptops. If the laptop is connected to the mains, the icon will look like - . If there is no connection to the mains and the laptop is running on battery power, the icon will look like - . We will consider the parameters of this mode in more detail below.
To the left of the above icons is a triangle (), by clicking on which program icons will appear (picture on the left). These programs install their own icons in the notification panel. As you can see in the figure, there are four installed programs. 
Not all programs place icons in this panel, and those that do, as a rule, may not have their own window on the screen and in the middle area of the taskbar. If you double-click on the program icon, the program window will appear on the monitor. This window can be closed, but the icon will remain. In order to close the program, you need to right-click on the icon and select Exit mode in the panel that appears (see the figure on the right).
This panel also includes a safe removal icon (). What is it for? After all, devices connected to USB can be turned on and off while the computer is running. Indeed, for example, a flash drive can be connected and disconnected and there will be no problems. But there are devices that lose data when disconnected. These include external hard drives. This happens because the external hard drive has a buffer in which data is stored, including for writing to the disk. If this data has not been transferred to disk, then it is lost, since when the power is turned off, the buffer will be reset to zero. In order to avoid this, this button exists. Click on it with the left or right button and a panel will appear on the screen (picture on the right) with a list of devices. Select the device and click on its name with the left mouse button. The device will be ready to turn off.
The panels of different programs have different modes, so we will not describe them.
Right-click on an empty space on the taskbar. In the panel that appears there is a mode Task Manager, which we will call. We have already looked at how to call this mode (using the Ctrl+Alt+Del keys). There are always several options on your computer to open programs or perform some action. This can be useful when calling a mode does not work and you can try using another method. To do this, right-click on an empty space on the taskbar and a panel with modes will appear on the screen, as shown in the figure on the right. Now to call the mode, click on the inscription Launch Task Manager.
Then select the Properties mode. A window will appear on the screen, the appearance of which is shown below.
First switch Pin the taskbar Allows you to pin the borders of the Quick Launch panel and notification area. If this switch is not enabled (there is no checkmark to the right of the name), then these borders can be moved using the mouse (the border view is shown on the right).
Switch Automatically hide the taskbar allows you to hide the bottom line (taskbar) so that the program window can be displayed on the entire screen. To make the taskbar appear, you must move the mouse cursor to the bottom edge of the screen.
Position of the taskbar on the screen allows you to set the taskbar at the bottom, top, right or left of the screen.
Taskbar buttons allows you to select a mode for grouping program icons on the taskbar. The mode was previously considered Always group, hide labels. That is, if one program is called several times, for example, a browser for working with the Internet, then there will be one rectangle on the taskbar. If you move the mouse cursor over it, a list of running copies will appear next to it. If you select the mode not to group, then each newly appeared program will correspond to a new rectangle. If you call the Explorer program 5 times, then there are five rectangles, and if the switch is turned off, then there is one. In the example below, Explorer is launched five times and Skype is launched once. As you can see, one of the rectangles is highlighted (with the inscription Libraries), that is, the background is lighter than that of the other rectangles.
If you click the Configure button in the field Notification area then in the window that appears (picture below) you can specify which icons should be displayed in this panel. You can also always display all the icons of this panel or hide some of them ( Hide unused icons).
We will leave consideration of other tabs of this mode for self-study, but they are rarely used in practice and therefore we do not describe them.
A computer monitor is a device designed to display visual (graphic, text, video) information.
Also, some monitors have built-in sound speakers and can thus reproduce sound, but this feature is not included in the main characteristics of the monitor.
When purchasing or assembling a personal computer (PC) from separate ones, you should definitely pay attention to the characteristics of the monitor, which we will consider below.
Previously, a monitor was called a display; now this name is rarely used.
Diagonal is measured in inches. 1 inch is equal to 2.54 centimeters. Previously, the measurement (“standard”) of an inch was the width of the thumb on an adult man’s hand. An inch when indicating the diagonal of a monitor is represented by a quotation mark “ - in the form of a double stroke. In English, inch is inch, abbreviated as in.
Most often you can find monitor models with diagonals of 15”, 17”, 19”, as well as 21”, 23” and 27 inches. The last option (27”) is more suitable for professional designers, photo editors, video editors, etc. Of course, ordinary users can also use it if they have the opportunity and desire to have a large monitor.
Monitors may have the same size in inches, but they will differ in proportions (Fig. 1).
Rice. 1 Monitors have the same diagonal, but different proportions
As for the proportions (the ratio of the length and width of the sides of the monitor), three formats are most widespread -
These numbers mean the following. 16:9 - this means that the width of the monitor (horizontally) is 16 conventional units, and the height of the monitor (vertical) is 9 of these same conventional units. More precisely, the width of the monitor is greater than its height by 16 divided by 9 times, that is, 1.78 times.
And, for example, a ratio of 4:3 means that the width is greater than the height by only 4 divided by 3 times, that is, 1.33 times.
Monitors with an aspect ratio of 16:9 and 16:10 are widescreen. They are good for watching widescreen and widescreen video movies. It is convenient to open several windows at the same time.
Monitors with an aspect ratio of 4:3 are convenient for those who work with editors, with graphic files, etc., but for others they are more familiar.
Monitors with an aspect ratio of 4:3 are often more convenient for work, and 16:9 for entertainment. Nowadays, widescreen monitors are also used more often for work, simply because they are more common.
Rice. 2 Two monitors in one housing
Widescreen monitors are convenient for those who like to work with several at once. Such users often use PC configurations with 2 (Fig. 2) or even 3 monitors at the same time.
The diagonal length and proportions of the monitor are what users pay attention to first, but the main characteristics of the monitor, of course, do not end there.
Currently, there are only two main types of monitors:
CRT monitor
As for CRT, this abbreviation stands for “cathode ray tube”.
These monitors are similar to old TVs (they are almost the same size and weight). They are older and are rarely used due to their large size, energy consumption and harm to the eyes.
Cathode ray tubes use high voltage, fast charged particles, and other technical things that are more harmful to users than more modern LCD displays.
LCD is an abbreviation for Liquid Crystal Display, which translates as liquid crystal display.
LCD monitors are more compact and lightweight because they can be almost flat in shape. Therefore, today they are used almost everywhere.
LCD monitor
The picture on LCD monitors is formed from a set of small dots (pixels), each of which can have a specific color. There are no harmful effects on the user and his eyes that cathode ray tubes had.
The first models of LCD monitors were slow, they could not reproduce fast-changing images without distortion, and therefore cathode ray displays were competitive for some time. However, technology does not stand still, and modern LCD monitors no longer have the disadvantages of their predecessors.
Today, when buying a monitor, you can see a varied range of exclusively LCD displays. Cathode ray tubes are becoming a thing of the past.
This is the number of pixels (the dots that make up the display) vertically and horizontally. The more pixels, the higher quality image can be obtained. And vice versa, the fewer there are, the more blurry, less clear, and lower quality the image will be. Therefore, if you want to see clearer pictures, you need to have more pixels.
In general, a pixel is the smallest point on a monitor screen. The whole picture is made up of such points. The more dots and the fewer these dots, the clearer the image. Hence the need to have more pixels to get better quality images.
Typically, resolution depends on the size of the display and its aspect ratio. For example, you can often find:
Numbers, for example, 1920x1080 mean:
– horizontally the monitor has 1920 pixels – the minimum points from which the image is composed,
– the monitor has 1080 pixels vertically,
– in total there are: 1920 multiplied by 1080 equals 2,073,600 pixels, that is, more than 2 million tiny dots, from which a beautiful, clear color image is formed.
In addition, the term pixel density is often used. Density is calculated using the formula “the number of points on any side divided by the length of this side.” This is needed to represent how many pixels are in one millimeter or one centimeter of the screen. But, as a rule, people have already gotten used to pixels, so the phrase “pixel density” is used much less often.
There are many types of matrices, they are not so easy to understand. They depend on the manufacturing technology of the matrix, and due to this they differ from each other in image quality, viewing angle, speed of image change and other parameters.
The viewing angle means that in some places the image is visible from all sides, and in others strictly at almost a right angle, so that the “neighbor” cannot see what is shown on your monitor.
The following types of matrices are distinguished:
– relatively inexpensive, but not the highest image quality TN+film panels. Their disadvantage is small viewing angles (move a little to the side and you won’t see anything), a decrease in brightness and contrast if you look at the image from the side and not at a right angle, etc.
– numerous IPS matrices with different nuances and differences from each other, having wide viewing angles, deep blacks, and good color rendition. Various types of such matrices can have both short (bad, slow) and fast (good, high-speed) response times, which allows slow matrices to be used for office work, and fast ones for watching videos, games and other applications that require fast graphics .
– VA matrices, PVA matrices and other types of matrices that differ from each other in response time (speed), color rendering, viewing angles and other characteristics.
Contrast is measured by comparing the brightness of the monitor's white and black pixels. The average value of this indicator is 1:700. The numbers mean that the brightness of black pixels is 700 times less than the brightness of white pixels, which is a very decent value. Although now it is quite common to find monitors with a contrast ratio of up to 1:1000.
The viewing angle affects from what position in relation to the monitor you can easily distinguish the picture. Many modern monitors have a viewing angle of 170-175 degrees.
We remember from school geometry that 180 degrees is a rotated angle, that is, looking at the monitor tangentially to its plane. Therefore, a viewing angle of 175 degrees is an opportunity to see the image even when standing to the side of the monitor. In other words, the picture is visible even if you direct your gaze almost parallel to the display.
Also quite a significant indicator. The shorter the response time, the faster the picture will change (pixels will respond faster to the signal).
High-quality modern monitors have a response time of 2-9 milliseconds. The number 9 milliseconds means that the image of each pixel can change more than 100 times per second.
And the number 2 milliseconds means the ability to change the image of each pixel 500 times in 1 second! We remember that the human eye no longer has time to distinguish between changes in a picture with a frequency of more than 24 times per second, and therefore 500 times per second is a very good result!
The faster the response, the better quality moving pictures the monitor can reproduce. Therefore, fans of computer games and those who like to watch high-quality films on a monitor screen prefer monitors with high response times, and are willing to pay extra money for this quality.
An important point when choosing a monitor is the option of connecting it to a computer. First of all, you need to know what connectors are on the computer.
If the monitor is selected for a desktop PC, then the computer may have different ports, for example DVI, VGA, HDMI.
Laptops usually use a VGA port to connect an external monitor.
But Apple computers use ports such as Mini DisplayPort and TunderBolt. All this should be kept in mind when choosing a monitor.
As a rule, monitors have the ability to connect to a DVI and (or) VGA port, but this must also be clarified.
If you need to connect the monitor to other ports, you may need special adapters with which the monitor can be connected to the computer. And then you need to take care of these adapters in advance.
Use icons to quickly launch an application or open a document. To do this, simply double-click on the desired icon.
There is another option for launching a program or opening a document that is hidden under the icon - using context menu. It appears when you click on the icon right mouse button. A list of actions that can be performed on the application or document appears next to the icon.
You can create your own folder directly on your Desktop. To do this, right-click on an area of the Desktop free from windows and icons and in the context menu that appears (Fig. 2.17) hover the mouse over the Create item. At this moment, a submenu will appear where you need to click on the word Folder (Fig. 2.18). As a result, a yellow folder icon will appear on the Desktop with “New Folder” written underneath it. Immediately enter the name you came up with for the folder on the keyboard (Fig. 2.19), and then press the Enter key on the keyboard. A new folder has been created.
Rice. 2.17. Calling the context menu
Rice. 2.18. Creating a folder
To delete a folder from the Desktop, just click on its icon with the mouse and then press the Delete (Del) key on the keyboard.Rice. 2.19. Entering a folder name
At the bottom of the screen there is a strip with a button and icons on it. This Paneltasks. Button
Start (Start) on the left edge of the Taskbar serves to call the Main Menu of Windows 7. We will talk about this menu later, but now we will discuss the remaining elements of the Taskbar. To the right of the button
Serves to open a browser (an application for browsing the Internet);
Start has several icons (usually three). These are buttons for quickly launching some applications. Let's look at each of them.
launches Explorer - an application for working with files and folders;
Opens the Windows Media video and audio player.
On the right edge of the Taskbar there is a button made in the form of a rectangle. When you click this button, all open windows are minimized, freeing up the Desktop.
Just to the left of this button the current time and date are displayed. If you hover your mouse over this location, the rectangle that appears will display the date with the letter indicating the month and day of the week.
There is a speaker icon next to the date
To the left of the speaker icon you can see the network readiness icon. If he has a cross
The system cannot connect to the network. For example, the cable is not connected to the computer’s network card or the system could not find a driver for the installed network card.
The leftmost element in this group is the current language indicator. Typically, in Russified operating systems, the choice is between two languages - Russian or English. The RU value indicates that Russian letters will currently appear when entering text from the keyboard. If the indicator displays the value EN, Latin letters will be entered.
Rice. 2.21. Language selection menu
To switch the language, you can click on the language indicator and select the desired language in the menu that appears (Fig. 2.21).
TO 
In addition, a key combination is used to switch the language. You can choose a combination of several options. By default (that is, immediately, without additional settings), the language is switched using a key combination Alt+ Shift
(Ctrl+Shift).
To add other languages, you need to select the “Options” command in the context menu of the language switcher, and in the dialog box, on the “General” tab, click the “Add” button. On the “Keyboard Switching” tab, you can change the keyboard shortcut to a more convenient one.
Buttons for running applications appear in the middle part of the Taskbar. The fact is that you can launch several applications at once, for each of which Windows 7 will open its own window. As already mentioned, you can minimize windows. In this case, the window disappears from the screen, but remains as a button on the Taskbar. You can click on the button on the Taskbar at any time, and the corresponding window will open. Moreover, it will become active, that is, it will be on top of other open windows.
You can make one or another window active either by clicking on it with the mouse, or by clicking on the button for this window on the Taskbar. You can also use the Alt+Tab key combination to switch between windows from left to right (Alt+Shift+Tab - from right to left, or hold down Alt and use the arrow keys on your keyboard). If you are using the Aero theme, you can use the Win+Tab key combination.
