if any computer fails it doesn't affect the entire system
Star topology.
A star topology is a method of connecting several computers to one another in a network. The cables used in a star topology are twisted pair cables or coaxial cables. Coaxial cables would be the cheapest solution.
bus topology.
Bus star ring mesh hybrid
Star Topology
Ring Topology, Mesh Topology, Bus Topology, Star Topology
Star
The most common LAN topology is that of a "star." In a star topology, each computer, or "node", is connected to a central hub. This is more reliable than a more classical "ring" topology, because a node failing will not bring down the entire network. A bus topology is arguably more reliable, but has poorer performance.
STAR-Bus
Star network,ring network,tree network,bus network
Star Topology, where Hubs can act as repeaters.
STAR Topology