These are all topologies, which mean physical arrangments 
of nodes(computer, printer and etc...)

In ring Network, every computer or devices has two adjacent 
neighbors for communication. In a ring network, all the 
communication messages travel in the same directory whether 
clockwise or anti clockwise. Any damage of the cable of any 
cable or device can result in the breakdown of the whole 
network. Ring topology now has become almost obsolete. 
FDDI, SONET or Token Ring Technology can be used to 
implement Ring Technology. Ring topologies can be found in 
office, school or small buildings
============================================================
=STAR
In the computer networking world the most commonly used 
topology in LAN is the star topology. Star topologies can 
be implemented in home, offices or even in a building. All 
the computers in the star topologies are connected to 
central devices like hub, switch or router. The 
functionality of all these devices is different. I have 
covered the detail of each networking devices in the 
separate portion of my website. Computers in a network are 
usually connected with the hub, switch or router with the 
Unshielded Twisted Pair (UTP) or Shielded Twisted Pair 
Cables.

As compared to the bus topology, a star network requires 
more devices & cables to complete anetwork. The failure of 
each node or cable in a star network, won’t take down the 
entire network

============================================================
=Tree Topology

Tree topologies are comprised of the multiple star 
topologies on a bus. Tree topologies integrate multiple 
star topologies together onto a bus. Only the hub devices 
can connect directly with the tree bus and each Hub 
functions as a root of a tree of the network devices. This 
bus/star/hybrid combination supports future expandability 
of the computer networks, much better than a bus or star.