You are always on REVNET, but to interact with it, all you need to do is run a program such as a web browser or email program.
Your computer needs a unique number to interact with the Internet, which is very similar to a phone number. The computers you interact with, through a web browser or email program for example, also need their own number. This number is known as an Internet protocol address.
Your cable modem provides the number via a box known as a router, which acts like a telephone exchange. If your cable modem, the computer port connecting the cable modem to your computer, Windows (or Macintosh) software system and our cables or boxes are all working, you are connected to the Internet whenever your computer is on!