The 'topic' content type allows you to create content categories. All members will need to choose an topic type when creating content.
The default types are news, blogs, and discussions.
You can decide to use the default types or define your own. You can even choose to have just one type enabled in case your community serves a very specific goal.
Some type examples other than the default ones:
When you have defined them, they will appear in the filters so that users can easily search for the content matching one of the categories.
Tip: Use a single topic type overview in your menu
When you type /all-topics behind the URL of your community, you will arrive at an overview of all topics on the site. It also has a filter for specific categories:
By selecting one of the types it shows the list of this type of content only. You can copy the URL and use it as a link in your menu. This is helpful if you want to highlight one specific category. For example, selecting 'blog':