Host Devices 

The network devices that people are most familiar with are called end devices or host devices. They are called end devices because they are at the end or edge of a network. They are also called host devices because they typically host network applications, such as web browsers and email clients, that use the network to provide services to the use

Intermediary Devices

Intermediary devices ensure that data flows from one host device to another host device

Intermediary Devices

• Switch - connects multiple devices to the network.

• Router - forwards traffic between networks. 

• Wireless router - connects multiple wireless devices to the network and may include a switch to connect wired hosts.

• Access point (AP) - connects to a wireless router and is used to extend the reach of a wireless network.

• Modem - connects a home or small office to the Internet

Network Media 

Communication across a network is carried on a medium. The medium provides the channel over which the message travels from source to destination. The plural for medium is media. The icons in Figure 3 represent different types of network media.