math.deg(x) turns value x into the angle from degrees into radians (so 360 will turn into 2pi)
math.rad(x) is the opposite of above (2pi will turn into 360 or 0)

math.huge() is really just a big number.

math.abs(x) returns the absolute value of a number. This is defined as the distance from zero. For example -1 is exactly 1 number away from 0 so it will return 1. 1 is also exactly 1 away from 0 so it will return 1. You can really think of it as just making x positive.