So, if we want to block any website, we only need add an entry for that website in the hosts file with a different IP address. By 'different IP address', i mean any IP other than the original IP of the website. The IP 127.0.0.1 is IP of your own computer. It is called loop back address. You can use this IP to block any website. If you use this IP, the application will try to connect to your own computer on its attempt to access the blocked website and thereby will fail to load the website.
hosts File in Windows
In Windows 7, Windows 8 or 8.1 and Windows 10, the hosts file can be found in the folder:
C:\Windows\System32\drivers\etc\
Here, C: is Windows installation drive.