Switches and hubs

• Networks are made up of many devices. To allow these devices to be connected in a way that makes cabling easier, hubs or switches are used.
• A hub will simply repeat messages to all connected devices. This is inefficient because it sends data to places other than its intended destination.
• A switch only sends a message to its intended destination device.
• The switch builds up a table with the MAC address of every device that is connected to each of its ports. When a signal is received, the data is analysed to determine the destination MAC address. The data is then sent to the port connected to the device with the MAC address.