I see these everywhere, but no one can come up with a consistent name for them from company to company. GXP is the closest I can come to a name for the bottom bracket.
Sram apex is a double chainring crankset which uses a GXP (aka Giga-X-Pipe) bottom bracket which is an external bearing bottom bracket.
I think External Bearing or Outboard bottom bracket are both commonly accepted terms, however there are several different incompatible types of external bottom brackets such as hollowtech, GXP, and Ultra Tourque.
The correct terminology is "GXP" or "GXP compatible crank set", for your SRAM Apex.
An outboard BB includes any BB which uses the same BSA or Italian threading as older style BB's, but places a larger bearing outside the frame, rather than a s,Allen bearing inside the frame. This increases BB stiffness and durability, while reducing weight. Unfortunately, unlike square taper BB's, there are many varieties of out board bearing BB's and they are not interchangeable.