Instance is like a server, it hosts your account and some communities.
Communities are like “subreddits”. It has to created / operated on one of the instances, but is accessible to all federated instances (which is largely the norm).
An analogy is email. You can choose your email provider (Gmail, Protonmail, Fastmail etc) and you will have an unique email address based on that provider (e.g. someguy@gmail.com is different from someguy@fastmail.com), but you will have the ability to send emails to anyone (unless you are blocked).
Something to add: when looking at the Reddit analogy, there is a really key difference to understand. While reddit.com is somewhat equivalent to a lemmy instance (eg lemmy.world), it’s important to understand that, while there is only one reddit, there are many many lemmy instances.
This means that when you talk about a subreddit (called a community in lemmy), you automatically know that the subreddit is a community located on reddit.com. If you talk about r/memes, it goes without saying that you are talking about reddit.com/r/memes.
When you shift to lemmy world, if you just talk about /c/memes, that may not be enough info to know which /c/memes you’re referring too. Are you talking about lemmy.world/c/memes? Or lemm.ee/c/memes? Or one of the hundred or more other communities named memes on another Lemmy instance?
Ok… so you’ve created an account on an instance. I’ll use lemmy.world as an example because that is where this discussion is hosted. Your account info is stored on lemmy.world servers. You are subject to the rules and administration of lemmy.world. Your “local” feed consists of posts made on lemmy.world communities.
BUT lemmy.world is also “federated” with many other instances. Take a look. The list is huge: https://lemmy.world/instances . This means that if you are on lemmy.world and choose to browse “all”, you will see communities and posts not just on lemmy.world, but also communities and posts on other federated instances. You can also subscribe to those communities so that they show up on your “subscribed” (aka “home”) feed. Note that there are complexities here around which content you will see from federated instances. At a high level just know that you don’t automatically see all content from other instances… you should put a pin in that topic and learn more about it once you have the general layout down.
Lemmy.world is also “defederated” with some instances as well, which means that their content and users are blocked from lemmy.world.
Simplified way to look at it:
Instance is like a server, it hosts your account and some communities.
Communities are like “subreddits”. It has to created / operated on one of the instances, but is accessible to all federated instances (which is largely the norm).
An analogy is email. You can choose your email provider (Gmail, Protonmail, Fastmail etc) and you will have an unique email address based on that provider (e.g. someguy@gmail.com is different from someguy@fastmail.com), but you will have the ability to send emails to anyone (unless you are blocked).
Something to add: when looking at the Reddit analogy, there is a really key difference to understand. While reddit.com is somewhat equivalent to a lemmy instance (eg lemmy.world), it’s important to understand that, while there is only one reddit, there are many many lemmy instances.
This means that when you talk about a subreddit (called a community in lemmy), you automatically know that the subreddit is a community located on reddit.com. If you talk about r/memes, it goes without saying that you are talking about reddit.com/r/memes.
When you shift to lemmy world, if you just talk about /c/memes, that may not be enough info to know which /c/memes you’re referring too. Are you talking about lemmy.world/c/memes? Or lemm.ee/c/memes? Or one of the hundred or more other communities named memes on another Lemmy instance?
Ok… so you’ve created an account on an instance. I’ll use lemmy.world as an example because that is where this discussion is hosted. Your account info is stored on lemmy.world servers. You are subject to the rules and administration of lemmy.world. Your “local” feed consists of posts made on lemmy.world communities.
BUT lemmy.world is also “federated” with many other instances. Take a look. The list is huge: https://lemmy.world/instances . This means that if you are on lemmy.world and choose to browse “all”, you will see communities and posts not just on lemmy.world, but also communities and posts on other federated instances. You can also subscribe to those communities so that they show up on your “subscribed” (aka “home”) feed. Note that there are complexities here around which content you will see from federated instances. At a high level just know that you don’t automatically see all content from other instances… you should put a pin in that topic and learn more about it once you have the general layout down.
Lemmy.world is also “defederated” with some instances as well, which means that their content and users are blocked from lemmy.world.