What is a Proxy?
What we call "proxy" is nothing more than a server mirroring a webpage so you can see it without accessing the website itself. This has many advantages. First of all, you have increased privacy. Servers usually keep track of who visits them. Furthermore, it is possible to make a recopilation of all the websites that you have ever visited. When using a proxy nobody will ever know what you visit online.
There are tens of thousands of proxies out there. They are becoming increasingly popular because of their benefits. It is true that some proxies are better than others so knowing what a proxy is and what to set as an standard is pretty useful.
The dictionary describes a proxy as "A computer network service that allows clients to make indirect network connections to other network services". That is a very complete description AND there is something important to be rescued: Proxies are not necessarily contained in sepparate websites. Your computer may act as a proxy if someone else connects to it just as you can connect to your neighbors computer and browse the internet making it look like he is actually browsing everything you see.