PPA stands for Personal Package Archive. It is a software repository that you can add to Ubuntu for the installation and continuous update of applications.
Installing software on Ubuntu is different than on Mac or Windows; some might say better. Rather than going to the web to download a package, it's usually a better bet to check the Ubuntu Software Center for any program you might want to install. This software is stored in a repository, which is a collection of software Ubuntu can download quickly and easily. Repositories are a more trustworthy way to download software than grabbing .exe files from random websites. Since everything in the default repositories is reviewed by the Ubuntu team before it goes out, you know everything there is completely safe for your system.
This is where PPAs come in. A PPA, or Personal Package Archive, is a collection of software not included in Ubuntu by default. Typically these repositories focus on a single program, but they can include more depending on the person maintaining them. Whatever the case, PPAs usually provide updates for your favourite software at a much quicker rate than Ubuntu itself. This is great, because you can decide which software you want to keep up to date and leave the rest to Ubuntu. Once you install new software with a PPA, updates will come to you through the Ubuntu Update Manager. This is fantastic, because it means all of your updates come through a single interface.
There are at least two ways how to add PPAs to your system: By user interface and terminal. The explanation regarding the user interface for Ubuntu 10.04 you find below.
For the terminal, please visit the following site:
Choose form the Menu: System > Administration > Software Sources You will be prompted for your password. Note that you can only add a PPA if you are an administrator user due to the security risks and system wide consequences of adding a PPA. Enter your password into the dialog to continue.
In the Software Sources window, click on the 'Other Software' tab and click the 'Add...' button. This will bring up a prompt asking for the 'APT line': Choose the Tab "Other Software" and click the "Add" button. This will bring up a prompt asking for the 'APT line'. Now you can type "ppa:" followed by the name of your PPA or copy and paste the command from a website: ppa:application-name-repository
Close the Software Sources window; you will be asked to reload your package information. Do this by clicking the 'Reload' button.
Now you can find the software packages from this PPA in your Ubuntu Software Centre. Open the Ubuntu Software Centre: Applications > Ubuntu Software Centre Type the name of the Application in the search folder (usually top-right), select the application and press "Install"