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.

World Record Facts
The most poisonous animal in the world is probably the two-toned arrow-poison frog – only 28 grams (1 ounce) of its poison could kill nearly 3 million people.      .. More >>