Bus Topology
Features
Bus topology uses a backbone (a cable, usually coaxial) to connect all the computers.
Computers connect to the main cable using either a vampire tap or a BNC T-connector.
Prone to attenuation, collisions, and signal loss.
Uses repeaters and amplifiers to boost signal.
Used for peer-to-peer networks.
Data is sent across the backbone until the destination computer is found.
Passive technology—the computers on the network listen for their "name" and only read that data.
The backbone has to be terminated on either end. Without termination, the data "falls off" the bus. If a device on the bus fails, the network fails.
Recommended for networks of 10 or fewer devices.
Advantages
Easy to connect a computer or peripheral to a linear bus.
Requires less cable length than a star topology.
Allows for longer cable length before attenuation.
Disadvantages
Entire network shuts down if there is a break in the main cable.
Terminators are required at both ends of the backbone cable.
Difficult to identify the problem if the entire network shuts down.
Not meant to be used as a stand-alone solution in a large building

Star Topology

Features
All devices connect to a central device.
All nodes (devices) communicate with the central device, which then makes the decision regarding which node the data is intended for, using a variety of methods (see "Networking Hardware"). The hub can send the signal to a single system or broadcast to all devices.
Usually uses UTP or STP cabling (Cat 5, 5e, 6).
Most common of the topologies, especially in small businesses and home environments, largely due to home routers becoming so common.
The central device can function as the repeater/amplifier.
Less concern for collision.
Can handle more systems attached to the network.
Works for peer-to-peer or client/server networks.
Advantages
Easy to install wire.
Scalable—easy to expand or reconfigure the network.
No disruptions to the network when connecting or removing devices.
Easy to detect faults and remove parts.
Disadvantages
Requires more cable length than linear bus topology.
Type of cable used usually has shorter length restrictions than the bus network.
If the hub or connector fails, the nodes are disconnected from the network