📑 Topics on this page (Jump to Topic):
📌 1. Types of Software
| Type | Meaning | Examples |
|---|---|---|
| System Software | Runs the hardware; base for other software | OS, device drivers, compilers, utilities |
| Application Software | Does a specific task for the user | MS Word, Excel, Tally, Photoshop, Browser |
| Utility Software | Maintenance/protection | Antivirus, Disk Cleanup, compression (WinZip) |
| Licence | Meaning |
|---|---|
| Freeware | Free of cost, but no source code |
| Shareware | Free trial for some time, then pay |
| Open Source | Source code available and modifiable — Linux, Firefox, LibreOffice |
| Proprietary | Owned by a company, closed source — Windows, MS Office |
⚠️ Exam Traps:
- Device driver = system software; antivirus = utility; MS Word = application.
- Freeware ≠ open source: freeware is free but the code is not given.
📌 2. Programming Languages & Translators
| Level | Description |
|---|---|
| Machine language (1GL) | Only 0s and 1s; understood directly by the computer, no translation |
| Assembly language (2GL) | Mnemonics (ADD, MOV); translated by an assembler |
| High-level (3GL) | C, C++, Java, Python, FORTRAN, COBOL, BASIC |
| 4GL | SQL, report generators |
| 5GL | AI/logic based — Prolog |
| Translator | Work |
|---|---|
| Assembler | Assembly → machine code |
| Compiler | Translates the whole program at once; faster execution (C, C++) |
| Interpreter | Translates and runs line by line (Python, BASIC) |
| Language | Fact |
|---|---|
| FORTRAN | First high-level language; scientific computing (John Backus, IBM) |
| COBOL | Business/banking |
| C | Dennis Ritchie, Bell Labs (1972); UNIX written in it |
| C++ | Bjarne Stroustrup |
| Java | James Gosling (Sun Microsystems); "Write once, run anywhere" |
| Python | Guido van Rossum |
| HTML | Markup language for web pages (not programming) |
- Bug = error in a program; debugging = removing errors. Syntax error = grammar error; logical error = wrong logic.
- Source code → (compiler) → object code.
- Algorithm = step-by-step solution; flowchart = its diagram.
⚠️ Exam Traps:
- Compiler: whole program at once; interpreter: one line at a time.
- Machine language needs no translator.
📌 3. Operating System (OS)
- The OS is an interface between the user and the hardware. It manages memory, processes, files, devices and security.
- Booting = starting the computer and loading the OS into RAM. Cold boot = from off; warm boot = restart.
- The kernel is the core of the OS; the shell carries user commands to the kernel.
| Type | Meaning |
|---|---|
| Batch | Groups of similar jobs run together |
| Multiprogramming / Multitasking | Several programs at the same time |
| Time-sharing | Each user gets a slice of CPU time |
| Real-time (RTOS) | Immediate response — missiles, medical devices, industrial control |
| Distributed / Network | Resources shared across many computers |
| OS | Fact |
|---|---|
| MS-DOS | CLI (command line interface), Microsoft, 1981 |
| Windows | GUI; Microsoft; first Windows 1.0 (1985) |
| UNIX | Bell Labs (Ken Thompson, Dennis Ritchie), 1969 |
| Linux | Linus Torvalds (1991); open source; Ubuntu, Fedora; BOSS (India) |
| macOS / iOS | Apple |
| Android | Based on the Linux kernel, Google |
Key Windows terms
- Desktop = first screen; taskbar = bar at the bottom; Start button; Recycle Bin = deleted files (Shift+Delete removes permanently).
- File Explorer for files and folders; Control Panel / Settings; Task Manager = Ctrl+Shift+Esc.
- These characters cannot be used in Windows file names: \ / : * ? " < > |
⚠️ Exam Traps:
- MS-DOS = CLI; Windows = GUI.
- Linux was created by Linus Torvalds; UNIX came from Bell Labs.
- Shift+Delete does not send the file to the Recycle Bin.
📌 4. Practice MCQs
📝 Practice MCQs (prepared by SF Prep — not PYQs)
Q1. Which of these is system software? Practice
Correct answer: (B)
The OS runs the hardware and supports other programs.
The OS runs the hardware and supports other programs.
Q2. A device driver belongs to which category of software? Practice
Correct answer: (C)
A driver connects the OS to the hardware — it is system software.
A driver connects the OS to the hardware — it is system software.
Q3. Which translator converts the whole program into machine code at once? Practice
Correct answer: (D)
A compiler translates the whole source code at once; an interpreter goes line by line.
A compiler translates the whole source code at once; an interpreter goes line by line.
Q4. What converts assembly language into machine language? Practice
Correct answer: (A)
An assembler converts mnemonics (ADD, MOV) into 0/1 code.
An assembler converts mnemonics (ADD, MOV) into 0/1 code.
Q5. Which language needs no translation? Practice
Correct answer: (B)
The computer directly understands machine language (0/1).
The computer directly understands machine language (0/1).
Q6. Which is considered the first high-level programming language? Practice
Correct answer: (C)
FORTRAN (FORmula TRANslation) was developed by John Backus (IBM) in the 1950s.
FORTRAN (FORmula TRANslation) was developed by John Backus (IBM) in the 1950s.
Q7. Who developed the C language? Practice
Correct answer: (D)
Dennis Ritchie created C at Bell Labs around 1972.
Dennis Ritchie created C at Bell Labs around 1972.
Q8. Who is the father of Java? Practice
Correct answer: (A)
James Gosling created Java at Sun Microsystems.
James Gosling created Java at Sun Microsystems.
Q9. What is HTML? Practice
Correct answer: (B)
HTML = HyperText Markup Language — it describes the structure of web pages.
HTML = HyperText Markup Language — it describes the structure of web pages.
Q10. Finding and removing errors in a program is called: Practice
Correct answer: (C)
A bug is an error; debugging removes it.
A bug is an error; debugging removes it.
Q11. The core part of an operating system is called the: Practice
Correct answer: (D)
The kernel directly manages memory, processes and devices.
The kernel directly manages memory, processes and devices.
Q12. Restarting a computer that is already on is called: Practice
Correct answer: (A)
Warm boot = restart; cold boot = starting from the off state.
Warm boot = restart; cold boot = starting from the off state.
Q13. Who developed the Linux operating system? Practice
Correct answer: (B)
Linus Torvalds released the Linux kernel in 1991; it is open source.
Linus Torvalds released the Linux kernel in 1991; it is open source.
Q14. What kind of interface does MS-DOS provide? Practice
Correct answer: (C)
In MS-DOS you type commands — a command line interface.
In MS-DOS you type commands — a command line interface.
Q15. Which type of OS is used for missile control and industrial robots? Practice
Correct answer: (D)
An RTOS responds within a fixed, very short time.
An RTOS responds within a fixed, very short time.
Q16. Software that is free for a trial period and then must be paid for is: Practice
Correct answer: (A)
Shareware = try before you buy.
Shareware = try before you buy.
Q17. Which of these is open-source software? Practice
Correct answer: (B)
The source code of LibreOffice, Linux and Firefox is public.
The source code of LibreOffice, Linux and Firefox is public.
Q18. The direct shortcut to open Task Manager in Windows is: Practice
Correct answer: (C)
Ctrl+Shift+Esc opens Task Manager directly.
Ctrl+Shift+Esc opens Task Manager directly.
Q19. The key combination to delete a file permanently without the Recycle Bin is: Practice
Correct answer: (D)
Shift+Delete removes the file permanently.
Shift+Delete removes the file permanently.
Q20. The Android operating system is based on which kernel? Practice
Correct answer: (A)
Android is developed by Google and based on the Linux kernel.
Android is developed by Google and based on the Linux kernel.