Adding tags in Joomla! 3 is super simple. There is a Tags component where you can manage individual tags, but you'll never have to touch that component because creating tags is easy within core items.
Here's how to add tags to an article:
1. Open an existing Article or create a new one.
2. Navigate to the right sidebar and locate the Tags field.
3. Clicking on the field will bring up a list of previously entered tags (if there are any).
4. Choose one to add OR start typing your own—hit return/enter when done entering your tag to add it to the list.
5. After adding all of your tags, be sure to Save your article.
Depending on how your template is set up, tags can be displayed in many different ways. Click on one of the tags below to see where they go.