Your application (client) fetches all posts from the people that you follow from all relays that you are connected to and displays them sorted by time, recent on top. This is the default.

Now some clients are getting smarter and sorting e.g. by the count of sats a post receives. And some clients will do additional fetching to get more context, etc.

It's evolving quickly, but ultimately you have freedom to choose the client and relays - and those can make some choices for you.

#Nostr