What They Call Pre-Labor

Saturday night I got painful, crampy contractions that spanned around the lower belly and the lower back, that would come, build up to painful, then fade, and came regularly for about 2 hours, then tapered off. I got pretty excited/panicky until I read in What to Expect When You're Expecting that this falls under "prelabor" and can go on for as much as a month! So, completely normal, especially in 2nd pregnancies. Have a few other things they list under "prelabor." It's confusing to figure out what's what, between prelabor, false labor, early labor, and first stage labor.