If you review a document, it means you read it and examine it (and maybe have some ideas to improve it) - but you don't make any changes.

If you revise a document, it means you change the text to correct errors or make improvements.

When preparing for a test, it's a good idea to study the material again in order to refresh your memory. American English speakers say you are reviewing for the test. British English speakers say you are revising for the test.

Fact
Polaris is the closest visible star to true north and is thus referred to as the North Star. By sometime around the year 2100, the wobble of the Earth's axis will slowly begin pointing the North Pole away from Polaris. By the year 14,000 A.D., the new North Star will be Vega.      .. More >>