Address 192.168.l.l is a default IP of some network devices (such as Linksys, Netgear, TP-Link and other manufacturers). Within the private IP address range: 192.168.0.0 – 192.168.255.255.
192.168.1.1 belongs to the IP address of the Class C network address, is reservations IP, devoted to the router settings. The password of this address will be different according to the router manufacturers' set.
An IP address generally has four segments, each divided from the other by a dot. The numbers cannot be generated randomly though, because they must be something in between 192.168.0.0 and 192.168.255.255 as far as private IP numbers are concerned.
While today these settings are good enough to secure your network, quite often keeping some of the settings at their default values (password, SSID) will put your network at risk. Everyone can easily find your default ID and password and gain access to your network and make some unwanted changes like changing your password for example.
192.168.1.1 is a private IP address because it can only be identified inside the network it is currently working in and not outside of it. So, when you add a new device to your network, make sure that its default IP address is not already in use.
The IP address 192.168.1.1 can be used to improve the security of your home network because it gives you access to your router settings via a web-based utility.