revolution vs resolution

The core difference

• revolution — a forcible change of government or order; a complete turn; a dramatic change. The industrial revolution, revolutions per minute, a revolution in medicine.
• resolution — a firm decision; a formal motion passed by a body; the settling of a problem; the detail an image or screen can show. Made a resolution to quit, the UN resolution, conflict resolution, high resolution.

The tell

Take off the -ution. Revolution is from revolve — something turns over, a wheel or a regime. Resolution is from resolve — something is settled, decided or broken into parts. A council passes a resolution; a mob starts a revolution.

In use

• revolution — The revolution toppled the monarchy. The drum turns at 1,200 revolutions a minute.
• resolution — She made a resolution to run every day. The council passed the resolution unopposed.

Common slips

• my New Year's revolution → my New Year's resolution
• the French Resolution → the French Revolution

Resolve a problem; revolve a wheel.

Where the words come from

Revolution is from Latin revolvere, "to roll back, turn over". Astronomers used it first for the turning of the planets; the political sense — a turning-over of government — arrived in the seventeenth century. Resolution is from Latin resolvere, "to loosen, to unbind", hence both "to solve" and "to decide". The optics sense is the same idea: the ability to separate fine detail into parts.