If you want the dictionary definition, just double click on any word.
expand vs

Expand is a transitive or intransitive verb. It means to increase in size, number or importance, or to make something increase.

For example: Jarp is expanding his vocabulary on the forum, but Hermine's says her hips are expanding as well.

Expend is a transitive verb. It means to use or spend something (especially time, effort or money).

For example: Teach expends a lot of energy running the Network.

For Jarp and Hermine