Table of Contents help summarize a document and allow readers to find a specific chapter they are looking for. Due to this, Microsoft Word has a included feature for Table of Contents that can be found in the References tab.
This table of contents uses the special text known as Headings in order to dictate what is considered a chapter in the document. These headings are usually the largest text on the page and usually include names for various chapters.
The Table of Contents is a nice addition to Word to improve readability on documents and books alike and help readers get to the information they are interested in or see what is coming up.