Package Management — Installing and managing software
apt
Package Management
Advanced Package Tool — Debian/Ubuntu package manager
Syntax
apt COMMAND [PACKAGE]
Examples
sudo apt update sudo apt upgrade sudo apt install nginx sudo apt remove nginx sudo apt autoremove sudo apt search python3
Common Flags
update refresh package index
upgrade upgrade all packages
install install a package
remove remove a package
autoremove remove unused dependencies
search search for packages
show show package details
Notes
Always run apt update before install to get the latest package list.
apt-get
Package Management
Classic APT command-line tool
Syntax
apt-get COMMAND [PACKAGE]
Examples
sudo apt-get update sudo apt-get install python3 sudo apt-get remove python3 sudo apt-get purge python3
Common Flags
update refresh package list
install install package
remove remove package (keep config)
purge remove package and config files
Notes
apt is the modern user-friendly version; apt-get is better for scripts.
pip
Package Management
Python package installer
Syntax
pip install [OPTIONS] PACKAGE
Examples
pip install flask pip install -r requirements.txt pip list pip freeze > requirements.txt pip uninstall flask
Common Flags
install install package
uninstall remove package
list list installed packages
freeze output installed packages
-r FILE install from requirements file
--upgrade upgrade a package
Notes
Always use pip inside a virtual environment (venv) to avoid system conflicts.
pip3
Package Management
Python 3 package installer
Syntax
pip3 install [OPTIONS] PACKAGE
Examples
pip3 install flask gunicorn pip3 install -r requirements.txt pip3 freeze > requirements.txt
Common Flags
Same flags as pip
Notes
Use pip3 explicitly when both Python 2 and 3 are installed.