However, all the communities hosted on lemmy.world will be inaccessible while it is down. If you really only care to look at one of those at a particular moment, lemmy might as well be down for you.
They'll still be accessible, since instances store local copies of data from servers that they're federated. Your interactions with those communities will be invisible to anyone outside your own instance until the instance hosting the community comes back up, though.
However, all the communities hosted on lemmy.world will be inaccessible while it is down. If you really only care to look at one of those at a particular moment, lemmy might as well be down for you.
They'll still be accessible, since instances store local copies of data from servers that they're federated. Your interactions with those communities will be invisible to anyone outside your own instance until the instance hosting the community comes back up, though.