Dead link
A hyperlink to a page that doesn’t exist any more on your website. Since it doesn’t lead to any page, it is called Dead link.

Deep linking
The practice of linking to the inner pages of another web site - as opposed to linking to the homepage. Although the vast majority of site owners don't mind deep links to their sites, it should be noted that deep linking has potential legal ramifications.

De-listing
Referring to the removal of pages from a search engine index. De-listing can occur at the request of the site owner or a variety of other reasons. Most often, de-listing occurs when a page breaks one of a search engine's submission rules, making itself guilty of some sort of spamdexing. The Search Engine Yearbook contains comprehensive guidelines to help you avoid spamdexing and de-listing.

Description
In the context of the search engines, the description refers to the descriptive text accompanied by a title and URL in the search results page. Some search engines take this description from the meta description while most generate their own from the page content. Directories often ask for a description when you submit your page.

Description tag
An HTML tag that gives a general description of the contents of the page. This description is not displayed on the page itself, but is largely intended to help the search engines index the page correctly. Some search engines use the description found in the description tag on their SERPs. A growing number of search engines are completely ignoring the description tag. For a more detailed look at the description tag and other types of meta tags, please refer to the Search Engine Yearbook.

Directory
A categorized listing of website, mostly compiled manually and listed. Directories can either be general (to the entire web) like ODP or Topical like the Dotcom Directory.

Dynamic content
Web site contents which are generated automatically based on some users’ action. Dynamic content changes regularly. Search engine Result pages are typical example of Dynamic contents as these are dynamically generated pages, changing based on users’ search keyword.