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# '''Main''' - preconfigured and your main Ubuntu support software# '''Main''' - preconfigured and your main Ubuntu support software repository# '''Universe''' - third-party free and open source software# '''Universe''' - third-party free and open source software === Add Repositories using Synaptic Package Manager ======Add Repositories using Synaptic Package Manager===Example: Repositories graphical interface (System -> Software and Updates)[[File:ubuntu-software-repositories01.jpg]]=== remove Repositories from the command line ===The repository can be removed also using the add-apt-repository command. sudo add-apt-repository --remove ppa:user/repository sudo apt-get update