1. Aptitude
1.1. Most Useful Commands
1.1.1. aptitude update, aptitude install, aptitude remove, aptitude clean, aptitude purge
1.1.2. aptitude search or aptitude show
1.1.3. aptitude download
1.1.4. Most Useful Commands
2. Advanced Packaging Tool (APT)
2.1. Most Useful Commands
2.1.1. USED with sudo
2.1.2. get
2.1.2.1. apt-get update
2.1.2.2. apt-get upgrade
2.1.2.3. apt-get install package-name(s)
2.1.2.4. apt-get remove package-name(s)
2.1.2.5. apt-get autoremove
2.1.2.6. apt-get clean
2.1.2.7. apt-get purge package-name(s)
2.1.3. cache
2.1.3.1. apt-cache search package-name(s)
2.1.3.2. apt-cache show package-name(s)
2.1.3.3. apt-cache depends package-name(s)
2.1.3.4. apt-cache rdepends package-name(s)
2.1.3.5. apt-cache pkgnames
3. If you still don't know what to do - manual !
4. DPKG
4.1. Most Useful Commands
4.1.1. dpkg -i package-file-name.deb
4.1.2. dpkg --list search-pattern
4.1.3. dpkg --configure package-name(s)
4.1.4. dpkg-reconfigure package-name(s)
5. Concepts
5.1. Features
5.1.1. Package downloading
5.1.2. Dependency resolution
5.1.3. A standard binary package format
5.1.4. Common installation and configuration locations
5.1.5. Additional system-related configuration and functionality
5.1.6. Quality control