Ubuntu 18.04 Hosts equivalent

Is there an equivalent to the Windows Hosts file which pre-empts the DNS lookups from URL searches from a browser?

The Linux equivalent is the hosts file located at /etc (i.e. /etc/hosts).

If you want to e.g. block Facebook, you can use a text editor such as Nano or Gedit to edit the file as superuser:

sudo gedit /etc/hosts

…and then add these lines in order to map the Facebook host to IPv4 0.0.0.0 and IPv6 ::0:

0.0.0.0         facebook.com
::0             facebook.com
0.0.0.0         www.facebook.com
::0             www.facebook.com

In order for these changes to take effect, you have to either reboot the system or run this command:

pkill -HUP dnsmasq