A computer network connects multiple computers together to share resources and information. There are several types of computer networks including local area networks (LANs) which connect computers in a small physical area like a home or office, wide area networks (WANs) which connect LANs across cities and countries, and metropolitan area networks (MANs) which connect networks across a larger region like a city. Common network topologies include star, ring, bus, and tree networks which determine how the connected computers communicate with each other.