Heather...this is what a tag is:
Tags are keywords and phrases that describe your Hub. Tags can be important for people using a search engine to find Internet material on topics. They alert the search engines that you have relevant material on the topic described by the tag.
Let’s say you were creating a tag for this Help page. Your tags might include words such as “Help”, “FAQ”, “Questions”. It’s wise to combine words to make phrases such as “HubPages help pages.”