DRAFT
Nav menu
The nav menu is displayed near the top of the topic lists. The available tabs are:
- Categories: Overview of the categories in the forum.
- Latest: All topics, in order of last activity.
- New: Here, only topics considered new will be listed. (Logged-in only)
- Unread: Here, only topics considered unread will be listed. (Logged-in only)
- Top: The most active topics in the last day, week, month, and year.
The leftmost item in the nav menu is the default tab, and it’s what you see when you click the Discourse logo or a category badge.
Topic Lists
There are several topic lists in Discourse. The first one you see as a new user will be the Categories page.
Categories page
The categories page gives you an overview of all the categories on the forum.
(screenshot)
Here we see that an entry in the categories page consists of the category badge, its definition, the badges of its subcategories, the avatars of repeat participants, a selection of recent topics, and the rate of new posts and topics.
Every topic has a category. Discourse, unlike older forums, encourages mostly flat categorization: there is only one subcategory level available, and all the topics go on the same list.
New and Unread topics
New topics are those that you have never read. By default, only topics created in the last two days will be considered New.
Topics considered New to you look like this: (screenshot)
There are two kinds of unread topics: those that you stopped reading, and those that have new posts.
Topics you stopped reading have a grey bubble with a number in it, representing the number of posts you haven’t read yet.
It looks like this: 
Topics that have new posts since you last read them have a blue bubble with a number in it, which is the count of new posts.
It looks like this: 
Top List
The Top list displays the ‘best’ posts from the past, by totaling up the topics’ posts, likes, and views.
There are several things on this page. On the first row, we have the Category filter, Nav menu items, and the Create Topic button.
You can use the Category filter to filter by category. For example, here is the top page, filtered to UX topics only:
A topic is displayed in a row on the list. Going from left to right, we have the title, the topic’s category, a list of participants’ avatars, the number of posts in the topic, the number of likes in the topic, the topic’s view count, and its creation and last activity dates.
Clicking on the title or post count will bring you to the last post that you read in the topic. Clicking on the like count will take you to the start of the topic in summary mode, if available. Clicking the topic start date will take you to the start of the topic, and clicking the last activity date will take you to the end of the topic.