Categories vs. Tags

There have been quite a few instances in the past months where I’ve had to explain the difference between a category and a tag to several people. I thought I’d share my definition and explanation of categories and tags to see if anyone else has a better definition.

Here are my definitions:
1) Tags are metadata (keywords?) for content. They describe the content itself and useful when searching a site.

2) Categories are used for navigation and represent different sections of a site where similar content is grouped. In most cases, categories are the sites navigation. Categories also had a hierarchy to a site. Even the word category can be used to describe categories. They categorize.

Categories are more broad and rigid while tags are more detailed and loose. Content is placed into categories while a tag is added to content. Tags also can be used to show relations between various pieces of content. For example, you have to pieces of content. One piece is in a category named Around Town and the second piece is in a category called Humor. These are two separate pieces of content but at one point they both talk about the presidential race. So a tag, presidential race, can be added to both pieces of content. With this one tag, we’ve established a relation between the two pieces of content even though they live on different parts of the site.

Now it is possible for content to live in more than one category, but this can become an issue because remember categories represent navigation on the site. When you start creating categories on the fly and posting the same pieces of content to a bunch of different categories, you are creating a confusing navigation experience for the user. The category structure should be flushed out with the creation of the site and a set of rules on adding new categories in the future should only be down with careful consideration. This is especially important when a site has multiple authors. Having a set of rules governing categories will help to keep the site’s navigation under control.

Many sites are using tags instead of categories to allow for a more flexible navigation. This works on some sites like Delicious since there really is no hierarchy. When you click on a tag, for example the tag “design”, you are actually performing a search for every piece of content that is tagged with “design.” This makes jumping around the site easy but there is no structure. Delicious does fake it though by using a URL schema that mimics a hierarchy, example http://delicious.com/tag/python+books+tutorial. That URL might seem like you are drilling down into the site but what is really happening is you are refining your tag search. More traditional sites still require some kind of hierarchy though because when just using tags, it’s easy to get lost in a site.

When used together, categories and tags can make finding content the reader is interested in extremely easy. The user has more options to get to the content on the site.