The Nikon Remote Wireless Flash System Is Easy To Use
Nikon's automatic wireless remote speedlight system makes it phenomenally Easy and convenient to use a couple of remote flashes (like Main light and Fill light). It allows Easy off-camera remote flash, and it provides an automatic point&shoot wireless remote TTL multiple flash system. Automatic setup is surely the largest factor for many people. Just set a flash or two out there and they can work. Immediate automatic TTL multiple flash setup, vs. tedious manual setup. However manual flash does offer absolute and full control, and the system can also be used as a wireless triggering system for manual flash power levels (which is NOT to be confused with Manual flash mode - it is still very much Commander/Remote operation, and incompatible with much manual flash gear, such as optical slaves).
Here is Nikon's Quick Guide for AWL setup instructions, with the menus of the various compatible gear.