A reference book is a collection of information compiled together (usually by some linked theme) so that it can easily be referenced. They are generally intended to be used to look up information rather than read cover to cover. Types of reference books include Dictionaries, Encyclopaedias, Atlases, etc.

In the context of this wiki a reference book is a work referring to some aspect of Star Trek usually approaching the subject as if it were fact rather than a view from our 'real world' into the Star Trek fictional world.