Note that the majority of the network is wired. Each item on the network has a wired connection. The key to connecting all the items is the Switch, which is at the hub of the network. The broadband router may simply be a wired version, but if some staff have wifi enabled laptops, then it can be used to let them connect to the Internet and also to the rest of the LAN. This way wireless systems can access the business fileservers. And communicate with other PCs on the LAN.
Most switches operate at 100Mbps that is the speed of Category 5 LAN cabling. It is possible to improve on this by using a Gigabit switch that operates at 1000Mbps. Some suppliers might say you will see an improvement with CAT 5 cabling, but to get realistic results, you'll need to have Cat 5e or CAT 6 cable installed
