Difference between the "catalog" and "category"?

Question

Answer

A catalog is a list of items in some order or system of classification.
It can also be used as a verb meaning to put items into a catalog.
A category is a group or set of things or people that have one or more common characteristics.
A catalog may contain one or more categories.  A catalog can also be in a category - "a tool catalog" or "a fashion catalog".

Answer

The two word are terribly different. Try a dictionary.