At one time, computer would have all the information it ever required, and ever would need, stored on inside it. If you wanted to put more info on it, you used physical media, for example CDs and Floppy disks.
This is now being replaced by the Net. If you want a data, then simply download it from the web. You never need to cope with a physical disk to install, use and dump a program. We now even send info the other way; storing things on the Net, using services like Web mail and online applications like Google Docs and Scribd. You will have heard the 'cloud computing' phrase attached to all this.