When a paper letter is sent, the postal service does not open it to decide what to do with it depending on its content or the identity of the sender. They are just paid to carry the letter. Their postal network is thus said neutral.
It is the same with the Internet: when no discrimination is applied regarding the emitter, the recipient, or the nature of the information being carried, the net is neutral2. Network operators do not decide whether using any service or application, or accessing any particular content, should have priority over the rest of the information flow. Thanks to this principle, everybody on the globe, regardless of their operator, has access to the same Internet.
Lets keep it that way
(CC)BySa - La Quadrature du Net - 2009