This is the IP address of the internal interface of the firewall. The
address used in this template is "192.168.1.1" with netmask
"255.255.255.0". This is rather typical address used for small and
home networks. Some commercial firewall appliances come preconfigured
with this address.
If your network uses address different from "192.168.1.0/24" used in
the template, you should change the address of the interface in the
editor panel and click "Apply". In addition to that, you will also
need to replace network object "net-192.168.1.0" used in several
Policy and NAT rules of the newly created firewall with network object
that has address matching your network configuration. See slideshow How to change IP
addresses in the firewall configuration created from template for
the demonstration of the procedure.