Each device connected to the switch has its own dedicated bandwidth. Put another way, if 8 computers share a 10Mbps hub, and all 8 are trying to send information through the hub at the same time, they each have only a share of the network's fastest potential speed. If bandwidth is shared equally you would have 10 divided by 8 equals 1.25Mbps. By contrast, a device connected to a port on a 10Mbps switch has a potential speed of 10Mbps, as do all of the other devices that are connected. When building a network, it is important to consider your future needs.
Switches are more scalable than hubs, since they can relay packets without slowing down the network.
A packet traveling through a hub, then through a number of secondary hubs, will see its communications speed split, first by the number of ports on the primary hub, then by the number of ports on the additional hub. In contrast, the delay caused to a network signal traveling through two layers of switches is virtually undetectable. You can only link up to four 10BaseT hubs in succession-any more, and network signals become corrupted. With 100BaseTX technology, you can only link up to two hubs in succession. By contrast, you can link switches in succession without limit.