I've been going through docs for the past couple of hours but I haven't understood what the PPA is? I have a cross-platform Java application that I'd like to publish to the Ubuntu Software Center. My application is open-source and I'm using Github.

Apparently, publishing applications to the store isn't as simple as uploading a deb package - am I right? I need to create an account on Launchpad and put all my code there.

I don't intend to move from Git to Bzr merely for the sake of publishing to the app store but luckily, one is able to set up source-code mirroring from Github to Launchpad.

Since my application is still very premature, it'll have updates fairly often. When I build my application on my machine, do I simply go my Ubuntu App Developer page and upload the new DEB package or do they build my application from source?

What exactly is the PPA for? I don't think I'll need too many of the Launchpad features so I'd like to stick to Github if possible.

(Publishing for Ubuntu really isn't trivial. I can see why there are so many developers out there who haven't published their applications to the Ubuntu Software Center. Publishing an Android applications has been the easiest so far.)