# User Management
sudo adduser username
# Adds a new user with the specified username.
sudo deluser username
# Deletes the specified user.
sudo passwd username
# Changes the password for the specified user.
# Package Management
sudo apt update
# Updates the package lists for upgrades and new package installations.
sudo apt upgrade
# Upgrades all the installed packages to their latest versions.
sudo apt install package_name
# Installs the specified package.
sudo apt remove package_name
# Removes the specified package.
# Service Management
sudo systemctl start service_name
# Starts the specified service.
sudo systemctl stop service_name
# Stops the specified service.
sudo systemctl restart service_name
# Restarts the specified service.
sudo systemctl enable service_name
# Enables the specified service to start on boot.
sudo systemctl status service_name
# Checks the status of the specified service.
# File System Management
df -h
# Displays disk space usage in a human-readable format.
du -sh /path/to/directory
# Displays the size of the specified directory.
sudo mount /dev/sdX1 /mnt
# Mounts the specified filesystem to the /mnt directory.
sudo umount /mnt
# Unmounts the filesystem mounted at /mnt.
# Network Management
ip a
# Displays all network interfaces and their statuses.
sudo systemctl restart networking
# Restarts the networking service.
netstat -tuln
# Displays network connections, routing tables, interface statistics, masquerade
connections, and multicast memberships.
# System Monitoring
top
# Displays real-time system information including CPU and memory usage.
free -h
# Displays memory usage in a human-readable format.
sudo journalctl -xe
# Displays the system logs with detailed information.
