Repeaters/hubs are used to connect together two or more network segments of any media type. In larger designs, signal quality begins to deteriorate as segments exceed their maximum length. Repeaters/hubs provide the signal amplification required to allow a segment to be extended a greater distance.
There are two kinds of hubs namely:
1. Passive repeaters/hubs simply forward any data packets they receive over one port from one work station to all the remaining ports.
2. Active repeaters/hubs, also sometimes referred to as multiport repeaters regenerates the data bits in order to maintain a strong signal.
An important fact to note about repeaters/hubs is that they only allow users to share ethernet.
A network of hub/repeaters is termed "Shared Ethernet", meaning that all members of the network are contending for transmission of data onto a single network (collision domain). This means that individual members of a shared network will only get a percentage of the available network bandwidth.