The FAR is the Federal Aviation Regulations, part of the Code of Federal Regulations that contains the text of regs that deal with all US agencies from the FAA to the FCC, the FTC, the banking agencies, the environmental agencies, the civil right agencies, etc...
The AIM is a general reference for pilots about many of the operation aspects of flying - how to communicate with ATC, how airspace works, etc.
ASA's FAR/AIM is a republication of the AIM and parts of the FAR ASA thinks a pilot should know. It's not even all of the FAR.
They are part of the group of information that you need to know as a pilot, but they are not even close to everything you need to know.