LAN
It is usually within a single building. It consists of computers and devices connected to hubs or switches. Connecting to a LAN allows you to be part of a WAN. Some advantages include the sharing of resources and communication between users. Some disadvantages are easier spread of viruses and slower access to external networks.
Ring Topology
The computers are connected in a ring. The data passes through all the computers before reaching the desired computer. They perform well under heavy loading and large networks can be made out of this type of topology. However adding a computer to an existing ring topology can be difficult. Also if there is a problem with the wiring between two computers, the network fails.