Whether using U.OSU for a class site, personal blog or portfolio, using categories and tags may be beneficial.
Adding tags or categories is not required, but may be a useful organizational tool to you and your readers as your site accrues more posts. Both categories and tags are about navigation and sorting. They are ways to group your content to help your visitors better find content.
What is a Category?
Consider categories as a structured and hierarchical collection of posts. You define the categories and their relationships ahead of time. For example, you might have multiple collections: homework assignments, exam prep, news items, etc. Each category encompasses a group of posts related to a specific collection.
What is a Tag?
Tags are less structured and more free-form. They are keywords that help your visitors search within and across categories. You can define tags ahead of time, or as you write posts. For example, you might use the tag "photosynthesis". This tag could appear in both homework assignment posts an posts within the exam prep category.
What's the Difference?
Tags are the keywords that help your reader search and know what's happening in the post. Categories are the collection of articles that fall under one general umbrella. For example, if you notice you are tagging every other post "news", "news" might make a good category. On the other hand, if you're tagging "highered" and "moocs" only a couple times, they might be better left as tags within a category.
For a course site, you could define categories for each of your major assignments, but leave tags relatively undefined. As students create posts to fulfill assignments, have them place each post in the proper category and then add tags to describe what they wrote. To see all posts related to an assignment, you can use the categories widget. To see every post about a topic that students have written about, you can search or filter using tags.
Ultimately, whether you use tags, categories or both depends on how you plan to use them. Both categories and tags are organizational tools to help you structure your site.
Note that categories and tags can only be assigned to posts.
See Adding Tags to a Post or Adding Categories to a Post for details about how to add each.
For more information about the difference between categories and tags, check out some additional resources: