Explain the common G-codes and M-codes used in CNC programming.

G-codes control machine movements: G00 (rapid positioning), G01 (linear interpolation), G02/G03 (circular interpolation CW/CCW), G17/18/19 (plane selection), G20/G21 (inch/metric units), G28 (home position), G40/41/42 (cutter compensation), G90/91 (absolute/incremental positioning). M-codes control machine functions: M00 (program stop), M03/M04 (spindle CW/CCW), M05 (spindle stop), M06 (tool change), M08/M09 (coolant on/off), M30 (program end). Understanding these is essential for CNC programming and troubleshooting.