You may have heard the term hub, switch or router when someone was talking about their work or home network. You may be wondering which the correct device for your network is and what the differences between the devices are. Well here is your answer.
A hub is a device that connects all you networked devices such as computers and printers together through a common shared point of access (or hub). It will usually consist of 4 or more RJ45 ports. RJ45 ports are used with network cables. The most common network cable in use today is Category 5 or Cat5. The connector on the ends looks like a slightly larger phone jack. A hub connects all the devices on its ports together. When data arrives at one port, it is sent to the other ports so that all the devices can see all the information, commonly called packets. When used in a large environment this is not efficient because all the packets are being sent to all the devices on the network causing traffic and collisions.
A switch is similar to a hub and servers generally the same purpose but is a bit smarter. It filters and forwards the packets on the same network so they go to where they are needed and not to every device. As a frame comes into the switch, the switch saves the originating MAC address and the originating port in the switch's MAC address table. The only time you will see traffic from other devices is when it is directed to the address of your computer.
A router forwards data packets to their destinations through a process known as routing. It transfers data between 2 separate networks such as your home network and the internet. A router communicates with other routers using routing protocols and then creates and maintains a routing table to keep track of what device is where. Routers use protocols such as ICMP to communicate with each other and configure the best route between any two hosts. Layer 3 switches can also route packets so keep that in mind when shopping for a switch.