This refers to a special block where the summary to a response to a specific query can be found. This also includes the link to the webpage from which the summary is found. Featured snippets are usually found if the query takes the form of a question.
A type of link that is placed at the bottom of the page. They are less and less being used by SEO optimization as they can be devalued by search engines nowadays. Additionally, the position of these links are unlikely seen by users and are overshadowed by anchor texts (hyperlinks found on the content).