A hub or concentrator is a device that channels the cabling of a network to extend it and repeat the same signal through different ports.
A hub is the technological device that has the ability to centralize the function of a network with the purpose of expanding it to other ports using the same signal that is repeated and issued successively.
The operation of a concentrator is given by the repetition of the same data packet on all its ports, so that all points access the same information at the same time. The hub is essential for the type of star networks.
Another alternative for this type of network is multi-port repeaters. A system in which communicating computers are connected in series to a line that connects them to each other. Multiport repeaters can be passive (they don't need electrical power), active (they do need it), or smart (they include a microprocessor and are called smart hubs).
Traditionally, hubs suffered from the problem that they could only support a single speed. If PC computers are easily upgradeable, other computers may be difficult to upgrade. A relationship between a switch and a hub or hub is considered a double speed hub.
In competition with a switch, the hub used to be a more economically priced option. Although today the switches are also accessible, the hub is suitable for special occasions. For example, a hub is useful for analyzing all traffic on a network segment. Another case is that with a switch it is easier for an inexperienced user to cause a data loop on the network. On the other hand, with a hub, it is more difficult for this to happen.
There are different types of hubs and concentrators on the market, for all economic possibilities and for all types of networks.