you can think of them as different windows into a similar structure. They look different, they’ll assemble the data a bit different, and might even send slightly different forms–but they’re close enough that it’s all legible, all interpretable into their formats.

And kbin and lemmy have very similar formats! But it’s possible for mastodon (the twitter analogue) to interact with kbin and lemmy as well. Even though they present the data in a different way, with different sorting criteria for your feed, and different ideas on how subscribing to a community or a person works, at the end of the day the formats are very similar: a parent post with a bunch of comments.