Computer Knowledge Questions for SSC CHSL

Hardware Fundamentals

Hardware is the physical, touchable part of a computer. Think of it like the body of a car — engine, wheels, steering wheel. The CPU (Central Processing Unit) is the brain that does all calculations. RAM (Random Access Memory) is temporary, fast memory used while the computer is running — like your desk workspace. ROM (Read-Only Memory) is permanent, slow memory that stores the computer's startup instructions. Storage devices like HDD (Hard Disk Drive) and SSD (Solid State Drive) permanently save your files — like a filing cabinet. Peripherals are input devices (keyboard, mouse, microphone) and output devices (monitor, printer, speaker).

• CPU = brain, does all processing and calculations
• RAM = temporary, fast memory; lost when power off (volatile)
• ROM = permanent, slow memory; cannot be changed by user (non-volatile)
• HDD vs SSD: HDD is slower but cheaper; SSD is faster but costlier
• Input devices: keyboard, mouse, scanner, microphone, touchpad
• Output devices: monitor, printer, speaker, projector

Software & Operating Systems

Software is the non-physical part — programs and instructions that tell hardware what to do. Operating System (OS) is the main software that manages hardware and lets you run other programs. Windows, macOS, and Linux are common OS examples. Application software includes MS Word, Excel, Photoshop — programs you use for specific tasks. System software includes drivers and utilities that keep the computer running smoothly. Firmware is software stored in ROM that controls hardware at the lowest level.

• OS manages hardware resources and acts as middleman between user and hardware
• Windows is most common OS in India; macOS for Apple; Linux is open-source
• Application software = user-facing programs (Word, Excel, Chrome, etc.)
• System software = background programs (drivers, antivirus, disk cleanup)
• Firmware = permanent software in ROM; controls hardware boot process
• Booting = process of starting the computer and loading OS into RAM

MS Office Basics (Word & Excel)

MS Word is used for document creation — letters, essays, reports. MS Excel is used for spreadsheets — data tables, calculations, charts. In Word, you format text (bold, italic, underline), insert images, and create tables. In Excel, cells are organized in rows and columns; you enter data and use formulas to calculate. A formula in Excel always starts with = sign. Common Excel functions: SUM (adds numbers), AVERAGE (finds mean), COUNT (counts cells with numbers), MAX/MIN (finds largest/smallest).

• Word: document editor for text, images, tables, formatting
• Excel: spreadsheet with rows (numbered 1,2,3...) and columns (A,B,C...)
• Cell reference: A1 means column A, row 1
• Formula in Excel always starts with = (e.g., =SUM(A1:A10))
• Common functions: SUM, AVERAGE, COUNT, MAX, MIN, IF
• Ctrl+S = Save, Ctrl+C = Copy, Ctrl+V = Paste, Ctrl+Z = Undo (works in both)

Internet & Web Basics

Internet is a global network of computers connected via cables and wireless signals. World Wide Web (WWW) is a system of documents and resources linked by hyperlinks — accessed via browsers like Chrome, Firefox, Edge. URL (Uniform Resource Locator) is the web address you type (e.g., www.google.com). Email is electronic mail — you send and receive messages via email clients like Gmail or Outlook. A browser is software that displays web pages. Search engines (Google, Bing) help you find information on the internet.

• Internet = network of networks; WWW = system of linked documents on internet
• Browser = software to view web pages (Chrome, Firefox, Edge, Safari)
• URL structure: protocol (http/https) + domain name + path
• Email = electronic messaging; requires email address (name@domain.com)
• Search engine = tool to find information (Google, Bing, Yahoo)
• Hyperlink = clickable link that takes you to another page or resource

Keyboard Shortcuts & Common Commands

Keyboard shortcuts are key combinations that perform actions faster than using mouse. Ctrl key (Control) is used with other keys for most shortcuts. These shortcuts work across Windows, Word, Excel, and most applications. Learning 10-15 common shortcuts can save you time in exams and real work. SSC CHSL frequently asks: 'Which shortcut opens Find dialog?' or 'What does Ctrl+B do?'

• Ctrl+A = Select All
• Ctrl+C = Copy, Ctrl+X = Cut, Ctrl+V = Paste
• Ctrl+Z = Undo, Ctrl+Y = Redo
• Ctrl+S = Save, Ctrl+P = Print
• Ctrl+F = Find/Search, Ctrl+H = Find & Replace
• Ctrl+B = Bold, Ctrl+I = Italic, Ctrl+U = Underline
• Alt+Tab = Switch between open programs
• Windows key + E = Open File Explorer
• Delete = remove file; Shift+Delete = permanently delete (bypass Recycle Bin)

Cybersecurity & Data Protection

Cybersecurity means protecting computers and data from unauthorized access or damage. A password is a secret code that only you know — should be strong (mix of letters, numbers, symbols). Antivirus is software that detects and removes malicious programs (viruses, malware, spyware). Firewall is a barrier that blocks unauthorized access to your computer. Phishing is a scam where attackers trick you into revealing personal information via fake emails or websites. Encryption converts data into a code so only authorized people can read it.

• Password = secret code; strong password has uppercase, lowercase, numbers, symbols
• Antivirus = software to detect and remove viruses, malware, spyware
• Firewall = security barrier that monitors and blocks suspicious network traffic
• Phishing = scam emails/websites pretending to be legitimate to steal data
• Encryption = converting data into unreadable code; only authorized users can decrypt
• Malware = malicious software (viruses, worms, trojans, ransomware)

File Management & Storage

Files are documents, images, videos, or programs stored on your computer. Folders (directories) are containers that organize files — like drawers in a filing cabinet. File extension (e.g., .docx, .xlsx, .jpg, .pdf) tells you the file type. Saving a file means storing it on your hard drive. Cloud storage (Google Drive, OneDrive, Dropbox) lets you save files on internet servers instead of your computer — accessible from anywhere. Backup means making a copy of important files to protect against loss.

• File = single document, image, or program; Folder = container for files
• File extension shows type: .docx (Word), .xlsx (Excel), .jpg (image), .pdf (document)
• Path = location of file (e.g., C:\Users\Documents\MyFile.docx)
• Cloud storage = saving files on internet servers (Google Drive, OneDrive, Dropbox)
• Backup = copy of files for protection; important for critical data
• Recycle Bin = temporary storage for deleted files; can be recovered unless emptied

• Confusing RAM and ROM: RAM is temporary and volatile (lost on power-off); ROM is permanent and non-volatile. SSC asks this distinction directly.
• Thinking Ctrl+Delete and Shift+Delete do the same thing: Ctrl+Delete moves to Recycle Bin; Shift+Delete permanently deletes. Exam often tests this.
• Mixing up browser and internet: Browser (Chrome, Firefox) is software; internet is the network. They are not the same.
• Forgetting the = sign in Excel formulas: Every formula MUST start with =. Without it, Excel treats it as text, not a calculation.
• Assuming all shortcuts work everywhere: Some shortcuts are Windows-specific or application-specific. Ctrl+B (Bold) works in Word but not in all programs.
• Confusing HDD and SSD: Both store data permanently, but SSD is faster (no moving parts) and HDD is slower (has spinning disk). SSC asks speed comparison.

• RAM = Rapid Access Memory (temporary, fast, volatile) vs ROM = Read-Only Memory (permanent, slow, non-volatile). Think: RAM is like your notebook (erasable), ROM is like a printed textbook (permanent).
• CPU = Control Processing Unit (brain), RAM = workspace, HDD/SSD = filing cabinet. Hardware is like a human body: CPU is brain, RAM is short-term memory, storage is long-term memory.
• Ctrl shortcuts: C=Copy, X=Cut, V=paste, Z=Undo, S=Save, P=Print, F=Find, B=Bold, I=Italic, U=Underline. Mnemonic: 'Copy-Cut-Paste-Undo-Save-Print-Find-Bold-Italic-Underline' — practice typing these.
• Phishing = fake fishing for your data. Antivirus = anti-virus (like antibodies fighting infection). Firewall = wall of fire blocking bad guys.
• OS = Operating System (Windows, macOS, Linux). Think: OS is the manager of the computer, like a principal managing a school.

• SSC CHSL Tier-1 typically has 5-8 computer questions, mostly definition-based or scenario-based. Expect: 'What is RAM?', 'Which key opens Find dialog?', 'What does Ctrl+B do?', 'Difference between HDD and SSD?'
• Keyboard shortcuts are HIGH-FREQUENCY. Learn the 15 shortcuts listed above by heart. SSC loves asking: 'To select all text, press ___?' Answer: Ctrl+A.
• MS Excel formula questions are common. Know that formulas start with =, and common functions like SUM, AVERAGE, COUNT. Example: 'What does =SUM(A1:A10) do?' Answer: Adds values from A1 to A10.
• Cybersecurity questions are increasing. Focus on password strength, antivirus, firewall, phishing, encryption. Recent papers ask: 'What is phishing?' or 'A strong password should contain ___?'
• Hardware vs Software distinction is tested. Know: hardware = physical (CPU, RAM, monitor), software = non-physical (Windows, Word, antivirus). Exam may ask: 'Which is hardware: keyboard or Word?'
• File extension questions appear occasionally. Know: .docx = Word, .xlsx = Excel, .jpg = image, .pdf = document, .exe = executable program.
• Time management: Computer Knowledge questions are usually quick (30-60 seconds each). Don't overthink. If you know the answer, move on. If unsure, make an educated guess and move.