Data, Software & Operating System
Data and information
Data means raw facts — numbers, words, images, sounds — that have no meaning on their own. When data is processed and organised so that it becomes useful, it is called information.
More examples: temperatures recorded every hour (data) → "today was the hottest day of the month" (information). Items scanned at a shop (data) → total bill and "you saved ₹120" (information).
Structured, semi-structured and unstructured data
| Type | Meaning | Examples |
|---|---|---|
| Structured | Fixed rows and columns, easy to search | Attendance register, Excel sheet, bank statement, database table |
| Semi-structured | Has tags or keys but not a fixed table | Email (to, subject, body), JSON, XML, HTML page |
| Unstructured | No predefined format | Photos, videos, voice notes, WhatsApp chats, social-media posts |
| Roll | Name | Class | Marks |
|---|---|---|---|
| 1 | Aarav | XI-A | 88 |
| 2 | Diya | XI-A | 93 |
| 3 | Kabir | XI-B | 76 |
What is software?
Software is a set of programs, data and documentation that tells the hardware what to do. Software is broadly divided into three groups.
System software
- Operating system — Windows, Linux, macOS, Android, iOS.
- Device drivers — small programs that let the OS talk to a particular device, e.g. a printer driver. Without the right driver, the printer does not work.
- System utilities — maintenance tools: antivirus, disk cleanup, disk defragmenter, backup, file compression (ZIP).
Language translators
A CPU only understands machine language (0s and 1s). Programmers write in high-level languages such as Python, C++ or Java because they are close to English. A translator converts this source code into machine code (object code).
Compiler
- Translates the whole program at once
- Creates an executable file (.exe)
- Shows all errors after compiling
- Program runs fast later
- C, C++
Interpreter
- Translates and runs line by line
- No separate executable file
- Stops at the first error
- Slower, but easy to test
- Python, JavaScript
An assembler converts assembly language into machine language.
Application software
| Type | Meaning | Examples |
|---|---|---|
| General purpose | Useful for many people | Word processor, spreadsheet, browser, photo editor, media player |
| Customised (tailor-made) | Made for one organisation’s need | School fee management, hospital billing, railway reservation |
Proprietary, freeware and open source
Operating system and its functions
An operating system (OS) is the most important system software. It sits between the user and the hardware, manages all resources and gives a platform for other programs.
| Function | What the OS does | Example |
|---|---|---|
| Process management | Starts, schedules and stops programs; shares CPU time | Music plays while you type |
| Memory management | Gives RAM to each program and takes it back | Closing an app frees RAM |
| File management | Creates folders, names, saves, deletes files | File Explorer |
| Device management | Controls devices through drivers | Pen drive detected automatically |
| Security | Login, passwords, permissions | Phone lock, app permissions |
| User interface | Lets the user give commands | Desktop, icons, touch |
User interfaces
| Interface | How you use it | Example |
|---|---|---|
| Command-line (CLI) | Type commands | Command Prompt, Linux terminal |
| Graphical (GUI) | Click icons, windows, menus | Windows desktop |
| Touch | Tap, swipe, pinch | Android, iOS |
| Voice | Speak | Alexa, Google Assistant, Siri |
| Gesture | Move hands or body | Gaming consoles, smart TVs |
Summary & practice
- Data = raw facts; information = processed, meaningful data.
- Software: system (OS, drivers, utilities), programming tools, application.
- Compiler translates all at once; interpreter line by line (Python).
- OS manages processes, memory, files, devices, security and the UI.
Classify: (a) Antivirus (b) Tally (c) Printer driver (d) Python interpreter (e) A school's admission software.
Answers: (a) system utility (b) general-purpose application (c) system software – driver (d) programming tool / translator (e) customised application.
