A Hosts File is a function between an operating system and an IP address in networking configurations. It is a local text file that associates web addresses and converts it to numerical protocols that are recognized under the Domain Name System. For example, the IP address 74.50.127.5 would point to web address www.google.com. A Hosts File can be set to loopback to the localhost by using 127.0.0.1 and this prevents a user or node remote access to a network.
In Windows, the Hosts File is located C:\Windows\System32\drivers\etc\hosts