Thread: Best split?

Hello, I am 5-10 and weigh 180 lbs. I am having trouble making my split for my workout. I am starting the p/rr/p/s workout scheme but would like to know others opinions on what is the best way to split up the body to work out everything once a week. I saw somebody's split as:
Day 1: Chest/shoulders/triceps
Day 2 Back/biceps
Day 3 : legs
Day 4: core

is that a good one? and what does core mean?

My goals are to gain weight but not get huge, (which would be impossible for me anyway, I am fairly small boned).

I posted that split. 5' 10" 180 is a good size. Your core is your abs and lower back.