Threads are a new feature in Discord that allows users to create temporary sub-channels for specific topics or focused conversation. It was released on July 27, 2021. Moderators can close threads at anytime.
Threads are archived after a specific timeframe, starting from 1 hour to a week.

A screenshot of the New Thread panel on desktop.
Related Permissions[]
The following permissions enable their following actions, and must be set on the channel that a thread is in.
Manage Threads:
- Force-archive threads, including others', keeping the chat history but cutting off the conversation. When this happens, only a user with Manage Messages can un-archive the thread.
- Set slowmode on a thread.
- Delete threads.
Use public Threads:
- Create threads if the user also has Send Messages.
- Post in public threads. (This does not require Send Messages permission in the channel.)

A screenshot of a new thread, including all of the possible actions.
Use private Threads:
- Create private threads if the user also has Send Messages.
- Post in private threads. (This does not require Send Messages permission in the channel.)
Send Messages:
- Create new threads.
Whoever created the thread (the thread owner) has the following powers:
- Rename the thread.
- Archive the thread.