A cutter location (CLData) refers to the position which a CNC milling machine has been instructed to hold a milling cutter by the G-code instructions.
Each line of motion controlling G-code consists of two parts: the type of motion from the last cutter location to the next cutter location (e.g. "G01" means linear, "G02" means circular), and the next cutter location itself (the cartesian point (20, 1.3, 4.409) in this example). "G01 X20Y1.3Z4.409"
The fundamental basis for creating the cutter paths suitable for Computer-aided manufacturing are functions that can find valid cutter locations, and stringing them together in a series.
There are two broad and conflicting approaches to the problem of generating valid cutter locations, given a CAD model and a tool definition.
Read more about Cutter Location: Cutter Location By Offsets, Cutter Location Against Triangles, ZMap