Gateway : A gateway is normally a computer that operates in all layers of OSI model. It takes an application message, reads it and interprets it. It can be used as a connecting device between two internetworks that use different models. It understands the format and contents of data and translate message from one format to another.Hub: Hub is a physical layer device used to connect multiple devices in the network. It has many ports. It uses half duplex transmission mode. If a device wants to connect to the network then it can be connected to one of these ports.Router : Router is a network layer device. It transform the message in the form of packets. It uses routing tables to transfer the data across the network.Switches : Switch is a data link layer device used to connect devices. It uses packet switching technology to send and receive the data across the network. Full duplex transmission mode is used in switching.