In the star topology, all the computers and other network devices connected to a central device called a hub. Each connected device requires a single cable to be connected to hub. A hub normally accept data from a sending computer and delivers it to the computer for which the data is addressed. Hence a star network is not a broadcast network, rather a point-to-point network.
Using a separate cable to connected to the hub allows the network to be expanded without disruption to the network. Because each computer uses a separate cable to connect to the hub, the failour of a network connection affects only the single machine concern. The other computers can continue to function normally.
Fast Ethernet 100base-TX and 100Base-FX in a star toology is the most commonly used LAN today. Ethernet and 1000Base-TX Gigabit Ethernet also use star topology.
1. Star networks are easily expanded without disruption to the network
2. Easy to add/remove device to/from network.
3. One break dose not bring whole network down.
4. Easy to troubleshoot and isolate problems.
5. Widely used centralized management
1. Costs are usually higher then with bus or ring networks.
2. Requires more cable then most of the other topologies.
3. If the hub fails, any device connected to it will not be able to access the network.