Let's say, for example, your webpage has a table of contents like this ...

Table of Contents

1. Homemade Soup

2. Canned Soup

3. Herbal Soups

Once you have set up your codes, the visitor can click on "Homemade Soup" (no.1 in the table of contents above) and automatically jump down the webpage to the "Homemade Soup" content-paragraphs below.