A book of abstract or an abstract refers to a summary of a conference proceeding, review, thesis, research article, or any in-depth analysis of a specific subject typically used to help readers quickly understand the purpose of a paper.
The proceedings and the Book of Abstracts, both get published in the book format either as an e-book or as a printed book or both.
Proceedings usually contain full-length peer-reviewed papers while the Book of Abstracts contains only abstracts or extended abstracts of the presented papers.
An abstract book is a collection of scientific abstracts compiled in a booklet and is intended for use by attendants of a conference where the various abstracts therein included will be presented.