How do remote events work if i want it between server and player client?

Hello, I was searching for this but i cant get a clear website to explain this. How do i use a remote event between the server (script) and the player client (local script). The event needs to be send to the player that activated the code.

You can use the FireClient method to send data to the client.

Example:

-- Server
RemoteEvent:FireClient(player, key)

-- Client
RemoteEvent.OnClientEvent:Connect(function(key)
	print(key)
end)