Player movement in a multiplayer game is a bit more complicated than that of a single player one. Rather than just alter positions client-side, we must alter ALL of our players' positions server-side. This prevents against cheats and makes sure no one can get an unfair advantage such as editing their player speed client-side.
Editing player positions server-side requires quite a bit of know-how when taking server latency into consideration. Here i'll teach you how to get a smooth running real-time game using:
00:00 Authoritative server movement
19:42 Client side prediction
33:40 Server reconciliation
52:23 Player interpolation