Insert and Overtype Mode
Insert mode is the default mode for editing in Word. It is useful for adding and changing words. It is also the most flexible because it does not erase existing text. Insert mode is recommended for most editing.
Overtype mode is useful when replacing a word or series of words. It is particularly useful when you want to change the ending of a sentence.
Be careful. You can easily type over text you want to keep.
If you find yourself in Overtype mode and start to panic, press the Insert key.