Name given to the Illustrations at beginning or end of a book chapter?

The illustrations at the beginning or end of a book chapter are called chapter headings or chapter illustrations.

Sometimes they are also referred to as:

* Chapter openers

* Chapter closers

* Chapter head illustrations

* Chapter tail illustrations

These illustrations can take many forms, such as:

* Decorative elements: These can be simple designs, patterns, or even abstract art.

* Thematic images: These images relate to the chapter's content, providing a visual representation of the main ideas.

* Quotes: These can be excerpts from the chapter itself or relevant quotes from other sources.

The specific name for the illustrations will depend on the style and design of the book.