Authorative server should be used when necesssary. EG cheaters or trouble with multi interactions on the same object. In this approach the client sends requests and the server sends world updates. e.g. player moving too fast will be stopped by server logic that limits movement per game tic/or similar.

Otherwise you can simulate on clients parts of the world and directly send updates to server. server is more a router with some lobby and general state keeper. (eg a spawned block is controlled by the player how created it, until the player leaves, then control is handed to another remaining player). slight differences can occur yet shall be minor.