Introductory (adjective)

1. Serving as an introduction or preparatory to something more extensive or important.
2. Serving as a preliminary step or a basic level in a course of study.

Origin:

Formed from the word 'introduce' with the suffix -tory.

Examples:

1. This chapter provides an introductory overview of the main topic.
2. She took an introductory course in computer science.
3. The introductory price for the new product is very attractive.
4. The introductory section of the book sets the stage for the rest of the story.
5. The introductory meeting was designed to familiarize everyone with the company's policies.