

Each client app looks slightly different. They are all just front-ends for whatever Lemmy instance you’re on. You are on the lemmy.world instance. I’m on the lemmy.sdf.org instance.
Lemmy is federated software. It works kind of like email. You can have a Google address or Yahoo or whatever and send email to anyone else. In the same way, everyone on lemmy.world can see what everyone on lemmy.today or europe.pub or most other instances posts and usually vice versa. Some instances are not federated with others because of philosophical disagreements between their users, but mostly everyone can see and respond to each others’ posts and comments, no matter what instance anyone is on. There are many instances so that there is less work for each instance administrator and so that no one group can decide what everyone else sees.
Also the fact that I.C.E. (internal combustion engine) vehicles are one of the major causes of climate change.