Defederating cuts off the whole instance. They just blocked those three piracy communities as far as I understand.

Remember that lemmy.world has to keep a copy of whatever content appears in a federated community on their servers, making them legally liable for the content. At least they just blocked the community instead of defederating.

A strength and a weakness. The strength, as you say, is being able to move to a different instance. However, the weakness is that Lemmy (the software) requires each instance to keep a copy of every federated post for its users to interact with. This means they have to host (and be legally liable for) data that they can’t police beyond blocking the community / instance.

How many ports are on that charger? I have a group that plays D&D using a VTT even when playing in person. A 240 watt charger could power 3 or 4 laptops, greatly reducing cable clutter.

It is the difference between nginx and apache: two pieces of software that do basically the same thing. With the exception of some naming conventions and UI differences, they are the same and both participate in the community in the same way.