Template: Excerpt (Defined)
This is a user-defined post excerpt. It should be displayed in place of the post content in archive-index pages. It can be longer than the automatically generated excerpts, and can have HTML tags.
Template: Excerpt (Generated)
This is the post content. It should be displayed in place of the auto-generated excerpt in single-page views. Archive-index pages should display an auto-generated excerpt of this content. Depending on Theme-defined filters, the length of the auto-generated excerpt will vary from Theme-to-Theme. The default length for auto-generated excerpts is 55 words, so to test the excerpt auto-generation, this post must have more than 55 words.
Be sure to test the formatting of the auto-generated excerpt, to ensure that it doesn’t create any layout problems. Also, ensure that any filters applied to the excerpt, such as excerpt_length and excerpt_more, display properly.