What is Star topology

The star topology connects nodes over a network using a central control unit called the Concentrater(Hub), Concentrater can be a Hub, a switch or a router. The hub is a device that transmits information from one node to another.
The following figure shows a typical star topology setup

In preceding figure , All computers are connected through a hub. If a computer transmit data to an another computer , Each data packet from source computer is firstly sent to the hub.The hub ,in turn, sends data packets to destination computer.

Advantages

Higher Scalability
 Can easily add nodes to a star based network by attaching the required node to the hub. How ever the number of nodes that you can connect to the hub depends on the capacity of the hub.

Ease in troubleshooting and maintenance.
It is easy to locate fault in a star setup.If a node becomes faulty, It does not affect the working of the hub, which,in turn,does no affect the other nodes of the network

Limitations

High Cost of Installation

Setting up a star topology requires a lot of cabling because all the nodes have to connect to the hub. in addition the hubs are very expensive.

Single Point of Failure

The hub is a single point for handling network communication. As a result , a failure in the hub can disrupt the entire network communication.