What Does a "Maintainer" Do?

[Artim]

Earlier before 3.6 came out, there was talk of systemback disappearing from Linux Lite "for lack of a maintainer."  What exactly is a maintainer and what does he or she do?  Could non-technical boy like me do that?  I can't write code or anything like that, but "maintaining" just sounds like "keeping it around and updated." 

Sorry for the rookie question, just wondering if there's a new way I can contribute.