Bandwidth is the maximum amount of data that can travel a communications path in a given time. It's usually measured in bits per second. The internet is basically a street. Each car is a computer that is connected by a network. Each computer's "size" is determined by the equipment used (for instance DSL gives 1.54 megs of bandwidth). Your computer's size would be like the size of your car. All the computers can be thought of uas traffic and the total badnwidth of the network can be thought of as the number of lanes. If you have a bunch of lanes and no other cars, your going to be able to drive as fast as you'd like. However, if there is only one lane, and a bunch of trucks in front of you, your going to be moving slowly. Therefore, you'll have to wait. For example, say you want to download a song that's 4 megs from a network that has 10 megs. If you're the only one downloading, you're set. If two more people try to downlaod, however, then you have 12 megs trying to be downloaded and only space for 10. There's traffic and someone will have to wait until there's 4 megs space to download. Now if there's 100 people trying to download, you're going to have to wait for a very long time. To compensate, buiness, colleges, etc. upgrade equipment to increase the bandwidth size (add lanes).