How to fix lag.

How do you fix lag?
That depends on what type of lag you are experiencing. Once you know the difference, it becomes easy to identify when you do inevitably lag during a game.

There are two types of lag, "local" lag, and "internet" lag.

Internet lag is what the original "lag" was. Internet lag happens when you press a button in the game, and that message goes out through your internet connection, but on its way to the game server, it gets delayed. It could be delayed because you are downloading, which bogs the message down, or it could be that the server is on the other side of the world, and it just takes ages to get there and back.
This causes some sometimes funny, but usually frustrating shenanigans in games.
You might stick your head around a wall, see a bunch of bad guys, and run away like a coward. But, somehow, even though are 2 metres around the wall, where the bad guys cannot possibly see you, they somehow get the kill on you. This happened because of internet lag. When you saw the bad guys, and pressed a button to run away, your computer sent a little message, called a "packet" to the games server, to tell it that you were running away. The problem is, sometimes the packet gets slowed down, because of the reason we talked about earlier. So by the time the packet gets to the server, the bad guys have already seen, and shot you, you just don't know it yet.
So how do you fix internet lag? There are a couple things you can do.

1. Pause any downloads or uploads. Uploading torrents will especially make you lag considerably.
2. Change server. If the game allows it, sort the server display by ping, from lowest to highest. If the ping of a server(how long it takes your computer to send a message to the server and get it back) is low, then you should get no lag. Anything below 200 is fine for mmorpgs, but most shooters need the ping below 100 or they become impossible to play.

The second type of lag, isn't really lag. Everyone calls it lag, but it is just your computer not being fast enough to handle the game. You can test if it is this type of lag, by turning all video settings down as far as you can. If the lag disappears when you do this, then it is hardware lag. Put simply, one of the parts or more in your computer are just too slow or old to run the game properly. The only way to fix this is to upgrade your computer or buy a new one.