PPAs or Personal Package Archives are basically software repositories that are used by Ubuntu systems…
How to transform your Ubuntu installation into a rolling release
Ubuntu users out there have two ways to go with their systems. Either they choose to follow the “standard” release that gets upgraded every six months, or choose the latest LTS (Long Term Support) which guarantees security updates and support for a five-year period. The problem with the first is that you’ll have to perform major upgrades to your system twice a year, while the issue with the latter is that you won’t get any major updates on parts of the system that you may care about using what’s latest.