Vocabularies allow you to sort and filter content, and display tags. For example, you may have a topic tag of "Environment" and you can tag content with that topic. You can then display content based on specific tags or filter content.
How to get to Vocabularies/taxonomy term
You can navigate to the vocabularies/taxonmy section of CivicTheme/Drupal by going to Structure>Taxonomy.
Topics and site sections
CivicTheme comes with two sets of taxonomy terms/vocabularies out-of-the-box: Site sections and Topics.