In Chapter 2, Understanding Local Area Networks, we introduced the use of switches within a LAN. Recall that a switch is a device that's used to forward traffic from one device to the next within a local network. By introducing a switch to our network, we are providing a means of segmenting the network into smaller, more manageable, and more efficient areas.
At a basic level, this segmentation leads to a reduction in collisions since each port on a switch is classed as its own collision domain. In the following diagram, each computer is connected to a port on the switch in the center and has formed its own collision domain:
Notice that this segmentation reduces collisions but doesn't remove them. The reason for this is that, in most modern switched networks, a switch port is only connected to one device...