Lemmy is a federated platform where each instance is run independently but can interact with all the other ones. lemmy.org is such an instance.

Your account is on it (written sulegulmen@lemmy.org) but I (KubrickFR@lemmy.world) can see and reply to your post on the community c/asklemmy (similar to r/something on Reddit)

Hope this is useful, I’m no expert…