What are Hub and Switch in Computer Network?

Hubs

A hub is a physical layer networking device which is used to connect multiple devices in a network. They are generally used to connect computers in a LAN.

A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast to every other port, without considering whether it is destined for a particular destination or not.

Switches

A switch is a data link layer networking device which connects devices in a network and uses packet switching to send and receive data over the network.

Like a hub, a switch also has many ports, to which computers are plugged in. However, when a data frame arrives at any port of a network switch, it examines the destination address and sends the frame to the corresponding device(s). Thus, it supports both unicast and multicast communications.

Differences between Hub and Switch

HubSwitchThey operate in the physical layer of the OSI model.They operate in the data link layer of the OSI model.It is a non-intelligent network device that sends message to all ports.It is an intelligent network device that sends message to selected destination ports.It primarily broadcasts messages.It is supports unicast, multicast and broadcast.Transmission mode is half duplex.Transmission mode is full duplex.Collisions may occurs during setup of transmission when more than one computers place data simultaneously in the corresponding ports.Collisions do not occur since the communication is full duplex.They are passive devices, they don’t have any software associated with it.They are active devices, equipped with network software.They generally have fewer ports of 4/12.The number of ports is higher – 24/48.