Difference between Introductory and First

Introductory

Part of speech: adjective

Definition: introducing; giving a preview or idea of

First

Part of speech: adjective

Definition: Having no predecessor. The ordinal number corresponding to one.

Part of speech: adverb

Definition: Before anything else; firstly.

Part of speech: noun

Definition: The person or thing in the first position.The first gear of an engine.Something that has never happened before; a new occurrence.first baseA first-class honours degree.A first-edition copy of some publication.

Example sentence: The truth will set you free, but first it will make you miserable.