Packages Sources

• ppa
• https://launchpad.net/ubuntu/+ppas
• sources.list
• /etc/apt/sources.list
• $ add-apt-repository
• main universe multiverse restricted
• Main - Officially supported software.
• Restricted - Supported software that is not available under a completely free license.
• Universe - Community maintained software, i.e. not officially supported software.
• Multiverse - Software that is not free.
• update server