A computer is an electronic machine that accepts data as input, processes it, and gives the result as output.
It is one of the most useful machines in modern life. Computers are used in schools, offices, hospitals, banks, homes, and many other places. A computer can store a large amount of data, perform calculations quickly, and help us complete work with accuracy.
Input means entering data into the computer. We use input devices such as a keyboard, mouse, scanner, microphone, and webcam. For example, when you type your name on the keyboard, that is input.
Processing means working on the input data. The Central Processing Unit (CPU) performs all the calculations and logical operations. It reads the input and converts it into meaningful information.
Output means the final result produced by the computer. We see output on a monitor, printer, speaker, or projector. For example, after typing and saving a document, the printed page is output.
A computer system has two main components: Hardware and Software.
Hardware refers to the physical parts of a computer that we can touch and see. Examples include the monitor, keyboard, mouse, CPU cabinet, printer, scanner, and speakers.
Software is a set of instructions that tells the computer what to do. We cannot touch software because it is a program, not a physical part.
Computers have many useful features that make them different from human beings.
A computer works very fast and can perform millions of operations in a second.
It gives correct results if the input and instructions are correct.
Once given instructions, a computer can work automatically without repeated human effort.
A computer can be used for many different tasks such as typing, drawing, calculation, and internet use.
It can store a huge amount of information and data for a long time.
Computers are dependable and can repeat the same task without losing quality.
Data can be protected using passwords, antivirus, and security settings.
A computer can run many programs and perform more than one task at the same time.
A folder is a place used to organize and store files. It helps us keep documents, photos, videos, and other items in separate groups. Folders make it easier to find information quickly.
A file is a collection of related information stored in a computer. A file may be a document, image, video, audio clip, or program. Every file has a name and usually a file extension such as .docx, .jpg, .mp3, or .pdf.
Computers store data in different memory units. Small units combine to make larger units.
| Unit | Size |
|---|---|
| Bit | 1 Bit |
| Byte | 8 Bits |
| Kilobyte (KB) | 1024 Bytes |
| Megabyte (MB) | 1024 KB |
| Gigabyte (GB) | 1024 MB |
| Terabyte (TB) | 1024 GB |
Function keys are special keys located at the top of the keyboard. They are labeled from F1 to F12 and are used to perform specific tasks quickly.
| Function Key | Use |
|---|---|
| F1 | Opens the Help window in most programs. |
| F2 | Renames a selected file or folder. |
| F3 | Opens the Search feature in many applications. |
| F4 | Displays the address bar list in File Explorer. Alt + F4 closes the active window. |
| F5 | Refreshes the current page, folder, or document. |
| F6 | Moves the cursor to the address bar in web browsers. |
| F7 | Starts spelling and grammar checking in MS Word. |
| F8 | Used to access Windows startup options during boot. |
| F9 | Refreshes fields in MS Word and sends/receives emails in Outlook. |
| F10 | Activates the menu bar of the current application. |
| F11 | Enables or exits full-screen mode in most web browsers. |
| F12 | Opens "Save As" in MS Word and Developer Tools in web browsers. |
Computer is an ______ device?