15 Apr Changing your host.txt files
The host file is a local way to change where a domain is hosted, you can specificy any domain and then an IP. This is an interstitial stage of moving hosting, this allows you locally change a sites hosting before the global Nameservers/DNS have updated.
Generally this file is located at: C:\Windows\System32\drivers\etc
You can also see this article  which has an extensive lists of OS and how to update the equivalent host files.