What causes a high ping / high latency?

When Internet speeds are quoted, figures are usually given in Megabits per second (Mbps), for example an 20 Mbps broadband connection, but this is really only half the picture. A figure in Mbps gives you an idea of the capacity (speed) of your Internet connection but is doesn’t tell you about latency, a measure of time delay from one networked point to another; the other half of the picture.Consider the analogy of a car travelling at 100 mph from A to B. This might sound fast but gives no indication of whether the car has driven the most direct route; if direct, fine; if from A to C to D to B the journey is going to take longer. So with network traffic; you might have a fast Internet connection, but if the route between the user’s computer and the server being accessed is indirect, response times will be slower.Lets pretend you are connecting to a game server based in London, UK. Players from the UK and Europe will generally have better connections than those who connect from the USA, Russia or further away. You may have very good internet where you live (such as Fibre-Optic broadband) but that won't overcome the fact you are further way from our server. The information sent from your computer still has to travel on physical phone wires to reach the game server.Now I mentioned a moment ago that you have a connection between the game server you are connected to and Valve. When you load up TF2 you have a automatically have a connection to Valves item servers, which is what allows you to access your backpack items, and the VAC system both of which are controlled by Valve.Even when you connect to a Valve owned game server, you become the 3rd connection point in a triangle of computers.There are other things that can make your connection feel slow. In most cases it is due to something else being downloaded to your computer while you are playing. This could be something you are doing intentionally like downloading a game off Steam, it could be due to a background update for a program on your computer, or it could be other devices in your household being used.