Okay,
You're a bit confused. You ms is your ping.
It's how long a packet takes to travel along your network to the destination and back.
There is 1000 Milliseconds (ms) in a second. If your ping is 400ms it's taking just under half a second to get the packet there and back.
That may sound extremely fast, however it isn't.
If you're ping is over 60ms you'll struggle to play most new titles.... if above 260-300ms you'll even struggle on the older ones and most servers will automatically kick.