ls: List directory contents.

cd: Change directory.

pwd: Print working directory.

mkdir: Make directory.

rm: Remove files or directories.

cp: Copy files or directories.

mv: Move or rename files or directories.

touch: Create an empty file or update the access and modification times of a file.

cat: Concatenate and display file content.

more: Display content of a file one screen at a time.

less: Display content of a file with backward navigation support.

head: Display the beginning of a file.

tail: Display the end of a file.

grep: Search for patterns in files.

find: Search for files and directories.

chmod: Change file permissions.

chown: Change file owner and group.

chgrp: Change group ownership.

sudo: Execute a command as the superuser or another user.

su: Switch user.

tar: Archive files.

gzip: Compress or decompress files.

gunzip: Decompress gzip files.

df: Display disk space usage.

du: Estimate file space usage.

free: Display amount of free and used memory in the system.

ps: Display information about processes.

top: Display dynamic real-time information about running processes.

kill: Terminate processes.

wget: Download files from the internet.

curl: Transfer data from or to a server.

ssh: Secure Shell remote login.

scp: Securely copy files between hosts on a network.

ping: Send ICMP echo requests to a host.

traceroute: Print the route that packets take to reach a network host.

netstat: Print network connections, routing tables, interface statistics, masquerade connections, and multicast memberships.

ifconfig: Configure network interfaces.

route: Display or manipulate the IP routing table.

iptables: Administration tool for IPv4 packet filtering and NAT.

hostname: Print or set the system's hostname.

uname: Print system information.

date: Display or set the system date and time.

cal: Display a calendar.

who: Display who is logged in.

w: Show who is logged in and what they are doing.

last: Display a list of last logged in users.

shutdown: Shutdown or restart the system.

reboot: Reboot the system.

tar: Archive files.

sort: Sort lines of text files.

uniq: Report or omit repeated lines.

wc: Print newline, word, and byte counts for each file.

grep: Search for patterns in files.

awk: A versatile programming language for text processing.

sed: Stream editor for filtering and transforming text.

awk: A versatile programming language for text processing.

mkfs: Build a Linux file system.

fdisk: Partition table manipulator.

mount: Mount a file system.

umount: Unmount a file system.

lsblk: List block devices.

ps: Display information about processes.

df: Display disk space usage.

top: Display dynamic real-time information about running processes.

kill: Terminate processes.

nice: Run a command with modified scheduling priority.

renice: Alter priority of running processes.

crontab: Schedule a command or script to run at a specified time.

at: Schedule a one-time task to run at a specified time.

watch: Execute a program periodically, showing output fullscreen.

nc: Arbitrary TCP and UDP connections and listens.

rsync: Remote file copy and synchronization.

curl: Transfer data from or to a server.

telnet: User interface to the TELNET protocol.

lsof: List open files.

killall: Kill processes by name.

bg: Resume suspended jobs in the background.

fg: Resume suspended jobs in the foreground.

jobs: List active jobs.

nohup: Run a command immune to hangups, with output to a non-tty.

screen: Terminal multiplexer with VT100/ANSI terminal emulation.

tmux: Terminal multiplexer.

chmod: Change file permissions.

chown: Change file owner and group.

chgrp: Change group ownership.

umask: Set default permissions.

passwd: Change user password.

useradd: Create a new user or update default new user information.

userdel: Delete a user account and related files.

usermod: Modify a user account.

groupadd: Create a new group.

groupdel: Delete a group.

groupmod: Modify a group.

sudo: Execute a command as the superuser or another user.

visudo: Edit the sudoers file safely.

adduser: Add a user to the system.

deluser: Remove a user from the system.

addgroup: Add a group to the system.

delgroup: Remove a group from the system.

passwd: Change user password.