apt (Advanced Package Tool) is the standard Debian/Ubuntu package manager. It manages .deb files and their dependencies.
Update package lists from repositories:
sudo apt update
Install a package:
sudo apt install package-name
Remove package but keep config:
sudo apt remove package-name
Remove package and config files:
sudo apt purge package-name
Upgrade installed packages:
sudo apt upgrade
Upgrade including dependency changes (riskier):
sudo apt full-upgrade
Find packages:
apt search keyword
apt search --names-only keyword
Show package details:
apt show package-name
List installed packages:
dpkg -l dpkg -l | grep keyword
List files in a package:
dpkg -L package-name
Check if package is installed:
dpkg -l package-name
apt-get is the older CLI with identical functionality:
apt-get update apt-get install package-name
Prefer apt for interactive use; apt-get for scripts (stable interface).
sudo apt update before installing to ensure fresh metadatasudo apt autoremove to clean up unused dependenciessudo apt-cache search is equivalent to apt searchsudo apt checksudo apt-mark hold package-namesudo apt-mark unhold package-name
apt is wrapper around dpkg (lower-level) and apt-cache (search). For most purposes, apt is sufficient.