Windows and Linux
Windows basics
- Desktop: main screen. Taskbar: bar at the bottom with the Start button and running programs. Recycle Bin: holds deleted files until emptied.
- File Explorer: manages files and folders. Task Manager: shows running processes, ends tasks. Settings (older: Control Panel): configure the system.
- Windows versions: Windows 10 (2015), Windows 11 (2021). Windows is made by Microsoft (founded by Bill Gates and Paul Allen, 1975).
- Safe mode: starts Windows with minimum drivers to fix problems.
Windows shortcuts
| Keys | Action |
|---|---|
Ctrl + C / Ctrl + X / Ctrl + V | Copy / Cut / Paste |
Ctrl + Z / Ctrl + Y | Undo / Redo |
Ctrl + A | Select all |
Alt + Tab | Switch between open programs |
Alt + F4 | Close the current window; on desktop, shut-down options |
Ctrl + Shift + Esc | Open Task Manager |
Win | Open Start menu |
Win + D | Show desktop |
Win + E | Open File Explorer |
Win + L | Lock the computer |
Win + R | Open the Run box |
Win + I | Open Settings |
Win + Shift + S | Screenshot (snip) tool |
PrtSc | Copy a screenshot to the clipboard |
F2 | Rename a selected file |
F5 | Refresh |
Delete | Send to Recycle Bin |
Shift + Delete | Delete permanently (skips Recycle Bin) |
Linux and Unix
- Unix was created at Bell Labs in 1969 by Ken Thompson and Dennis Ritchie.
- Linux is an open-source, Unix-like kernel written by Linus Torvalds in 1991, released under the GNU GPL. Its mascot is Tux the penguin.
- Distributions: Ubuntu, Debian, Fedora, Red Hat, Kali (security testing). Android uses the Linux kernel.
- India: BOSS (Bharat Operating System Solutions) by C-DAC is an Indian Linux distribution. Maya OS by DRDO is an Ubuntu-based OS for defence use.
Common Linux commands
| Command | Use |
|---|---|
pwd | Show the current directory |
ls | List files |
cd | Change directory |
mkdir / rmdir | Make / remove a directory |
cp / mv / rm | Copy / move or rename / delete |
touch | Create an empty file |
cat | Show file contents |
grep | Search text |
chmod / chown | Change permissions / owner |
ps / top / kill | Show processes / live usage / end a process |
sudo | Run a command with administrator rights |
man | Show the manual of a command |
df / du | Disk free space / disk usage |
Keep practising
Notes are only half the work. Test yourself with questions and discuss doubts with other aspirants.
Prepared for exam revision from standard computer textbooks, Microsoft documentation and official sources. Features differ between Excel and Word versions (2016, 2019, 2021, 365) so check which version your exam follows. Found a mistake? Tell us.