Search Engine Optimization Tutorials by SEO Professionals

Dead Link

A link which is no longer functional.

Most large high quality websites have at least a few dead links in them, but the ratio of good links to dead links can be seen as a sign of information quality.

Deep Link

A link which points to an internal page within a website.

When links grow naturally typically most high quality websites have many links pointing at interior pages. When you request links from other websites it makes sense to request a link from their most targeted relevant page to your most targeted relevant page. Some webmasters even create content based on easy linking opportunities they think up.

Dedicated Server

Server which is limited to serving one website or a small collection of websites owned by a single person.

Dedicated servers tend to be more reliable than shared (or virtual) servers. Dedicated servers usually run from $100 to $500 a month. Virtual servers typically run from $5 to $50 per month.

Deep Link Ratio

The ratio of links pointing to internal pages to overall links pointing at a website.

A high deep link ratio is typically a sign of a legitimate natural link profile.

De-Listing

Temporarily or permanently becoming de-indexed from a directory or search engine.

De-indexing may be due to any of the following:

* Pages on new websites (or sites with limited link authority relative to their size) may be temporarily de-indexed until the search engine does a deep spidering and re-cache of the web.

* During some updates search engines readjust crawl priorities.

o You need a significant number of high quality links to get a large website well indexed and keep it well indexed.

o Duplicate content filters, inbound and outbound link quality, or other information quality related issues may also relate to re-adjusted crawl priorities.

* Pages which have changed location and are not properly redirected, or pages which are down when a search engine tries to crawl them may be temporarily de-indexed.

* Search Spam:

o If a website tripped an automatic spam filter it may return to the search index anywhere from a few days to a few months after the problem has been fixed.

o If a website is editorially removed by a human you may need to contact the search engine directly to request reinclusion.

Del.icio.us

Popular social bookmarking website.

Demographics

Statistical data or characteristics which define segments of a population.

Some internet marketing platforms, such as AdCenter and AdWords, allow you to target ads at websites or searchers who fit amongst a specific demographic. Some common demographic data points are gender, age, income, education, location, etc.

Description

Directories and search engines provide a short description near each listing which aims to add context to the title.

High quality directories typically prefer the description describes what the site is about rather than something that is overtly promotional in nature. Search engines typically

* use a description from a trusted directory (such as DMOZ or the Yahoo! Directory) for homepages of sites listed in those directories

* use the page meta description (especially if it is relevant to the search query and has the words from the search query in it)

* attempt to extract a description from the page content which is relevant for the particular search query and ranking page (this is called a snippet)

* or some combination of the above

Digg

Social news site where users vote on which stories get the most exposure and become the most popular.

Directory

A categorized catalog of websites, typically manually organized by topical editorial experts.

Some directories cater to specific niche topics, while others are more comprehensive in nature. Major search engines likely place significant weight on links from DMOZ and the Yahoo! Directory. Smaller and less established general directories likely pull less weight. If a directory does not exercise editorial control over listings search engines will not be likely to trust their links at all.

DMOZ

The Open Directory Project is the largest human edited directory of websites. DMOZ is owned by AOL, and is primarily ran by volunteer editors.

DNS

Domain Name Server or Domain Name System. A naming scheme mechanism used to help resolve a domain name / host name to a specific TCP/IP Address.

Domain

Scheme used for logical or location organization of the web. Many people also use the word domain to refer to a specific website.

Doorway Pages

Pages designed to rank for highly targeted search queries, typically designed to redirect searchers to a page with other advertisements.

Some webmasters cloak thousands of doorway pages on trusted domains, and rake in a boatload of cash until they are caught and de-listed. If the page would have a unique purpose outside of search then search engines are generally fine with it, but if the page only exists because search engines exist then search engines are more likely to frown on the behavior.

Dreamweaver

Popular web development and editing software offering a what you see is what you get interface.

Duplicate Content

Content which is duplicate or near duplicate in nature.

Search engines do not want to index multiple versions of similar content. For example, printer friendly pages may be search engine unfriendly duplicates. Also, many automated content generation techniques rely on recycling content, so some search engines are somewhat strict in filtering out content they deem to be similar or nearly duplicate in nature.

Dynamic Content

Content which changes over time or uses a dynamic language such as PHP to help render the page.

In the past search engines were less aggressive at indexing dynamic content than they currently are. While they have greatly improved their ability to index dynamic content it is still preferable to use URL rewriting to help make dynamic content look static in nature.