Just think about it like reddit and email had a baby: !subreddit@email.com.

subreddit is now called a community

email.com is now called an instance

When you send a normal email message, you need to know the person’s email address. On Lemmy, each comment, post, user, and community gets its own unique “email address”. When you share something, you tell everybody this email address. The instance someone is using when they click the address is smart enough to find and open all the posts/comments/etc associated with that address.

If you share it as a normal link, it’s like forcing a Gmail user to switch to Hotmail just to open the one email. They might not have a Hotmail account, so they can’t respond or interact with it without going back to Gmail first.

I just imagine a federated, YouTube-like platform. Except better in literally every single way. You are a member of your local community instance, and thereby connected with every other federated instance throughout the world.