A tag is a simple label or keyword you can use to categorize your Backpack pages any way you want. Then when you click a tag you can see all the other pages that have that tag. It’s a great way to keep your pages loosely grouped in ways that make sense to you.
For example, if you have a page called “Sales meetings” you might want to tag that page “business, meeting, sales, office” or whatever you feel best describes this page. Here's a walkthrough on how to add and use tags in Backpack:
To add a tag, click the "Tags" link at the top of the page you want to tag.
Then add your tags and click the "Add these tags" button. Separate each tag with a space and use quotes for tags with more than one word ("new business").
Once you've tagged a page (you can add as many tags as you want to a page), you'll see the tags at the top of the page.
Clicking a tag will show all the other pages with that tag. Or, you can click the "My Pages" link in your sidebar. On that page you'll see a list of all the tags you've created.
Click a tag and you'll see the list of pages that match that tag.