• Host File is like first referenced address book which associates hostname with IP address.
• Location of hosts file
• Block a site: Avoid ads by pointing ad sites with your local IP address
• Test one server in a cluster: you may hit any server in the cluster by default. If you want to test one specific server, add host entry
• DNS issues: When DNS has issues, HOSTS file is a workaround
• Host Header: At times, you may be able to open a site with IP address but you have to use website (without DNS entry). HOSTS file is the only option