1. File and Directory Management
5. Package Management
2. File Viewing and Editing
3. System Information
6. Process Management
7. Network Management
4. User and Group Management
ls: lists a directory's content
pwd: print working directory
cd: change directory
mkdir: creates a new directory
rmdir: deletes an empty directory permanently
cp: copies files and directories, including its content
mv: moves or renames files or directories
rm: deletes files permanently
ps: shows list of running processes
top: provides a view os the system's performance
kill: terminates a running processes
clear: clears terminal screen
touch: creates a new empty file
uname: prints machine's kernel, name and hardware
df: displays overall disk usage
du: checks a file or directory's storage consumption
free: displays RAM usage information
lscpu: displays CPU architecture information
lsblk: lists block devices
man: displays the manual page for the command
cat: displays the content of a file
less: displays the contents of a file or a command output, one page at a time
File or text editors: nano, vi, vim, gedit
killall: terminates all processes
htop: monitors system processes in realtime
pstree: shows the running processes as a tree
passwd: The /etc/passwd file is a text file that describes user login accounts for the system
useradd: creates a new user or update default new user information
userdel: deletes a user account and related files
usermod: modifies a user account
groupadd: creates a new group
groupdel: deletes a group
group: user group file
id: prints real and effective user and group IDs
Arch Linux: pacman
Debian/Ubuntu: apt-get, dpkg
RedHat Package Manager: yum, dnf, rpm
whatis: displays one-line manual page descriptions
sudo: root user
exit: exits from current user
date: displays date
timedatectl: displays time and date
history: shows command history
hostname -i: shows the IP address
whoami: displays the username of the current user
diff: compares directories or files
tail / head: shows the last 10 lines of a file by default
ifconfig/ip a: displays all IP addresses
ping: used for communication check
traceroute: shows how packets are being routed
netstat: Netstat displays network information (network connections, routing tables)
nslookup: query name servers to find information about resource records
dig: gets info about DNS name servers
ssh: connects to a remote server