Split - the regular routine that maps what day is designated for what muscle group.
The major benefit of incorporating a split routine is that you maximize your efforts in a more reduced time, rather than spending excessive time to do a full body workout. Having a clear idea of what you want to work before entering the gym, will focus your plan on working out and create a sense of fluidity to your routine. It is important to actually think out your routine so that it makes some kind of sense.
When forming your split, you want to initially look at your life schedule. Don't create a 6-day routine if you only workout 4 times during the week. Keep a good rotation of routines, so that there is regular work put on muscle groups.
The following are sample splits that can be used as the framework for your own:
5-Day Split (less involved):
Monday: Chest, Back, Arms, Abs
Tuesday: Hams, Quads, Calves
Thursday: Chest, Back, Arms, Abs
Friday: Hams, Quads, Calves
6-Day Split (more involved):
Monday: Chest, Tris, Abs
Tuesday: Back, Bis, Abs
Wednesday: Shoulders, Legs
Thursday: Chest, Tris, Abs
Friday: Back, Bis, Abs
Saturday: Shoulders, Legs
Over time you will be able to fine tune your split to reflect your personal goals and aspirations. Some people remove leg day from their routine to get ready for beach bodies in a short amount of time. Others may work antagonist muscles, like "Chest/Bis" to optimize bicep force. It's all dependent on your growth and body understanding.
With this being said, go forth and get Gainz.
"May unoccupied machines, forever be in your favor."