Tagging is the Web 2.0 version of adding metadata to web content, but with an interesting user-generated twist that the earliest forms of metadata lacked.

A W3C recommendation document defined a set of meta tags for web content, including the “keywords” tag. This tag allowed a content owner to add additional descriptive keywords, specifically for the benefit of search engines, that wouldn’t be seen by searchers or users who accessed a web page directly in a browser.

Fast forward to today, and webmasters can still add meta keywords to pages. But they can also explicitly recommended suggested tags for users to add when saving content to a bookmarking service like Del.icio.us or submitting to a user voting site like Digg. Some users tag with the recommended terms, but others add their own descriptive tags. This expands the universe of tags associated with content, potentially offering more options for users to find the content via search.

Today’s Search Illustrated graphic illustrates this concept:

Graphic by Elliance, an eMarketing firm specializing in results-driven search engine marketing, web site design, and outbound eMarketing campaigns. The firm is the creator of the ennect online marketing toolkit. The Search Illustrated column appears Tuesdays at Search Engine Land.

Opinions expressed in the article are those of the guest author and not necessarily Search Engine Land.

Related Topics: Infographics | Search Illustrated