A gigabyte switch is a device, similar to a hub or a router, that connects multiple networkable devices together. It is a specific type of the broader category known as network switches, which come in varying speeds. Compared with hubs and routers, a switch falls roughly in the middle in terms of capabilities and cost, with hubs being the most basic and routers being the most advanced type of networking device.
Using gigabyte as the prefix in the context of networking is somewhat of a misnomer, since, traditionally, bits are used to describe bandwidth, whereas bytes are used to describe storage totals. So, more commonly, routers, hubs, and switches — for which bandwidth is the key specification — are referenced in terms of megabits or gigabits. Devices like hard drives, for which total capacity is the useful descriptor, are in megabytes and gigabytes. In most cases, when someone refers to a gigabyte switch, they are really talking about a gigabit switch.
The main difference between a gigabyte switch, or any kind of switch for that matter, and a hub, is how they handle what is known as collision domains. Hubs are 'dumb' in the sense that they do not assign different addresses to the devices they are connecting, and do not direct network traffic to specific devices. This means that each computer, printer, or other machine is sending and receiving data along the same lines. While not an issue if there are relatively few devices online, this can become a problem as more and more are added, and network speeds decline rapidly. A switch is capable of organizing data transmissions; allowing for greater speeds, even with a large number of devices using bandwidth; and multiple simultaneous communications.
As compared to a gigabyte switch, older and slower standards of switch bandwidth speeds are 10 and 100 megabits. A gigabyte switch is commonly referred to as 1,000 for easy comparison. Different devices may support different bandwidth speeds, and not every gigabit switch backward-compatible with 10 or 100 megabit devices. Therefore, when assessing different switches, compatibility is typically noted by the presence of 10, 10|100, 10|100|1000, or other combination in the specs.
In order to enjoy the maximum bandwidth available with a gigabyte switch, it is important to use the right cabling. Cat5 cables are not capable of gigabit speeds, so a home or office with this older cable standard will need to upgrade to Cat5e or Cat6 cables to achieve the maximum possible speeds. This is an often overlooked and generally the most labor-intensive part of upgrading a network to the gigabit standard.