Dimensions and tolerances typically apply when the part is in its "free state" and not being forced or bolted down. Key Components of GD&T in Y14.5M-1994

A rectangular box that serves as the primary "sentence" for GD&T. It contains the geometric symbol, the tolerance value, material modifiers (like MMC or LMC ), and datum references.

Imaginary, mathematically perfect points, axes, or planes used as reference points for measurements.