
The format for the files under the /etc/apt// directory is the same as for the regular sources.list file. Generally, third-party repositories have only one category. The default Ubuntu repositories are split into four components - main, restricted, universe and multiverse. The last entries are the repository components or categories.


The first method is by using the add-apt-repository command and the second one is to manually add the repository using a text editor. In this tutorial, we will show you two ways to add apt repository on Ubuntu and Debian systems. While there are thousands of application available in the default Ubuntu repositories, sometimes you may need to install software from a 3rd party repository. An APT repository is a network server or a local directory containing deb packages and metadata files that are readable by the APT tools. When installing packages using the Ubuntu Software Center or the command line utilities such as apt or apt-get the packages are downloaded from one or more apt software repositories.
