For mechanics certificates, there is the airframe and powerplant ratings, and then inspection authorization. A&P school teaches everything from helicopters to dope and fabric to turbine engines, that is, it is all encompassing. In the real word you will most likely obtain specialized training for the airframes/engines you will be working on via official manufacturer training programs or hands on experience. Most of the programs require you to have your A&P to be enrolled. Initial A&P School touches on a lot of subjects but not in depth enough for you to step out into the workforce ready to kick @ss and take names. But as far as the FAA is concerned the A&P and IA is all you need on your certificate, and that's all there is.