AutoCorrect lists allow text replacement on the fly, and make typing of long expressions faster. Once you prepared a list containing the abbreviations you want to replace, and the expressions that should replace them, memoQ makes the necessary changes automatically. For example, you may want to define that memoQ should replace "FYI" with the expression "For your information", or JB with the name John Brown, it is all done as soon as you enter these letters. This can save you a lot of time.
AutoCorrect also corrects capitalization. If you failed to press Shift to capitalize a word fast enough, while you are typing the first letter of a word, memoQ will correct it. If you turn on CAPS LOCK by accident, AutoCorrect is correcting this as well.
See also: Edit AutoCorrect settings