It's very similar to Lemmy, and probably the closest to Lemmy out of the other platforms that follow this format.
We tried to describe the differences here
https://fedecan.ca/en/guide/fedecan/our-platforms#forum-style
These platforms follow a forum format, similar to platforms like Reddit or Hacker News. You can share and discuss links, text, and images, and upvote/downvote content to decide on what content rises to the top.
These platforms use one of two projects under the hood:
- Lemmy - Lemmy is an established and stable project. It was designed to be very fast and reliable, and it makes up a large part of the forum side of the Fediverse
- Piefed - Piefed is a relatively new project that is growing in popularity. It offers new ways to organize content, such as topic lists, feeds, flairs, and additional moderation tools.
As they're both federated, you can use any of them to connect to the wider Fediverse!