SuperCab and extended cab??

Looking into buying a used truck but wanted to know if there was any diffrece between SuperCab and extended cab or is it just a year to year example this years is crew cab, Leg room our seats diffrent??

Im sure ill be corrected if im wrong, but I think supercabs have four actual doors where as extended cabs are the basic cab but longer with less room in the actual cab. Thats my opinion.

some supercabs (extendedcabs) have 4 doors, but its the full front doors, then like a half back door. it works like sucide doors. a supercrew has the full 4 doors that looks like a 4 door car.