Building your content with predefined keywords or categories is an excellent way to group or organise your content to be retrieved by others.

If the content you create is specific to busineses in a business directory, you could for example create a category called "Businesses" and list the voabulary terms in that category (e.g. plumber, builder, accountant, etc).

Taxonomies and categories can be set up and locked from change by the site owner, or if required, allow the users to add new taxonomies where they do not yet exist in your system (in true web 2.0 style).

Once you create a vocabulary you can list various terms and enable:

• hierarchical tagging (multiple levels of depth)
• multiple keyword tagging (many tags to the same piece of content)
• free tagging (where the user can add tags to content themselves if the tag does not exist, thus growing the richness of a database)

Once your content is tagged you can even name your site URL pages dynamically on the basis of the categories (preserving user friendly names).

You can create categories for certain content types (pages, forms, blogs) or across all content types.