Hubs

Hub, sometimes referred to as a concentrator or repeater Hub, refers to a networking component which acts as a convergence point of a Network, allowing the transfer of data packets.
In its simplest form, a hub works by duplicating the data packets received via one Port, and making it available to all ports, therefore allowing data sharing between all devices connected to the hub.
A passive hub simply allows the data packets to flow through it, a manageable hub allows the data transfer to be monitored and the ports to be configured individually.