How does a player rise in rank?
There are two types of rank. There is Battle Experience (BEPs), and Command Experience (CEPs). Player gain BEPs by killing players, destroying objects, and taking base complexes. Players gain CEPs being the Commander of a Squad that takes a base complex. Thus, five-star Commanders are those folks that have led many squads to successfully take many base complexes. There are quite a few benefits to CEP rank (oriented to command of groups) that are over and above the benefits of BEP rank (which is how you get certifications, hangar slots, and implant slots).