Having a latency is different to a lag, lag is computer based and the speed of the cPU, GPU and RAM have an effect on it. Ping or Latency is purely network based. It depends on the distance from your computer to your ISP to the server you are trying to connect to. So the further the distance, the higher the latency. Nothing can be done except looking for closer ISPs and game servers.
Correct me if I am wrong