Keywords are certain words in your blog post that are searchable.
For example, in the blog post (see below) about autism, notice that two of the keywords on the left, under the Category and Tags tab are autism, Bittersweet Farms, etc. When a reader is searching for those topics, your blog post could pop up.
To add a keyword, follow these steps:
1. Log into your site by going to Wordpress.com
2. Click on My Site
3. Click on the words Blog Posts (to edit existing blog post), or the Add button to add a new blog post
4. If adding keywords to an existing blog post, find that blog post then hit the Edit button and open up the blog post.
5. In the left menu, Click on Categories & Tags
6. Write your keywords that you should pull out of your blog post. Typically, add your keywords after you write your blog post so you know what words to use.