Tag
Tags provide a useful way to group related posts together and to quickly tell readers what a post is about. Tags also make it easier for people to find your content. They usually don't have a hierarchy and can easily be applied across multiple categories. Here's a simple example of how a set of pets might be tagged and categorized.
Pet tags
- Friendly
- Professionally trained
- Adoptable
Pet categories
- Cats
- Dogs
- Rabbits
- Birds
- Fish
Notice that it's difficult to have a pet be two of the same category (you can't be a cat and a dog at the same time), but it's pretty easy to apply two tags to the same pet (it can be both friendly and professionally trained). Generally speaking, if you're working with a set of content, your types will be in categories, and your traits will be in tags. In the case of a set of degree programs, you would likely have a category for master's degrees, and you might have tags for "online" and "in-person"—ways you can complete the classwork for that master's degree. In the case of a set of news, you might have Alumni News and Research News as categories, and "technology" and "arts"—subject areas that could apply to both alumni and researchers—as tags.