G90, G91 (Set Distance Mode)
To make the current point have the coordinates you want (without motion), program G92 X… Interpretation of RS274/NGC code can be in one of two distance modes: absolute or incremental.
To go into absolute distance mode, program G90. In absolute distance mode, axis numbers (X, Y, Z, A, B, C) usually represent positions in terms of the currently active coordinate system.
To go into incremental distance mode, program G91. In incremental distance mode, axis numbers (X, Y, Z, A, B, C) usually represent a distance from the current values of the numbers.
I and J numbers always represent increments, regardless of the distance mode.