What information can find our web browser about us or our system?

Many times when we went to a web page, we see a banner that shows the information about our equipment or signage in the language or geographical area from which we connect. For example, a banner with our IP and our ISP or Google advertisements only for the city from we are connecting, etc ...
The best thing to protect part of our privacy is to use a proxy, as published recently, or some anonymous surfing web.

But ... what can find my web browser about me and my computer?

A good website for these data is http://browserspy.dk/. On this page we perform several tests to check your privacy. This is the main page, in which different parts are distinguished: in the center publish news about web sites that speak of it. On the right there are various tests to perform, and that is the part that interests us.

Multiproxy chains to leave no trace in Internet

A proxy is a program that makes Internet access to your computer instead. It's like somewhere between a computer connected to the Internet and the server you are accessing. When we surf through a proxy, we're not actually going directly to the server, but we make a request on the proxy and it is he who connects to the server that we want to access and returns the result of the application. (Wikipedia)
There are several programs to perform this task. At this time we will do using SocksChain, which you can download from here.
Once installed and running, we see that the interface is this: