To autofit the width of a column in a Word table,

CONCEPT: In a Microsoft Word table, a column's width is not fixed - the built-in AutoFit feature can resize a column so it exactly matches the widest content inside it. This can be triggered either from the ribbon (Layout tab, Cell Size group, AutoFit, then AutoFit Contents) or directly on the table grid by double-clicking one specific column boundary.

APPLICATION: The boundary that carries this shortcut is the column's RIGHT border. Double-clicking that border tells Word to shrink or expand the column so its width exactly fits the longest entry inside it - the same result as using Layout tab -> Cell Size -> AutoFit -> AutoFit Contents from the ribbon.

CROSS-CHECK / CONTRAST:
- Double-clicking the LEFT border of a column is not a recognized AutoFit trigger in Word; it has no defined width-changing effect.
- Double-clicking directly on the column header (away from any border) selects the column's cells for formatting - it does not recalculate width.
- Since only one of the three described actions actually triggers AutoFit, treating every listed action as equivalent overstates what happens.