A root word is a word you can change into a new word by adding a beginning and/or an ending.

A prefix is a beginning that is added to a root word.

For example, take the root word "purpose." By adding the prefix "multi" to "purpose," the new word "multipurpose" is formed.

Every prefix has its own meaning. When added to a root word, a prefix changes the meaning of the root word to which it is added. The root word "purpose" means "an aim or a goal one wishes to achieve." The prefix "multi" means "many." The new word "multipurpose" means "designed or used for many purposes."