It's already simple enough.

A BA is short for "Bachelor's of Art" degree from a university. A BA is given when a person studies something in liberal arts such as history or language. They typically take about 4 years to get, if a person takes classes full time. An AA is an "Associate's of Art" from a community college (in the US, anyway, universities don't usually give Associates degrees). It is given in the same fields as the BA, but it is for a shorter program and does not carry as much value as a BA, meaning that the jobs available for someone with an AA will not be as good of jobs as someone with a BA.

Can you provide context? They could mean several things in a university (including what you said).