The IP 192.168.1.1 is the first element of a range of IP addresses reserved for private use, so no organization owns it. Homes and organizations can use the 192.168.x.x IP address range for internal routing.
A router allows users to share an Internet connection between several computers. While the router uses an Internet-facing IP address to communicate with other computers on the Internet, it needs to use a separate range of numbers to keep track of devices connected to it. Many routers use addresses that start with 192.168 to assign to connected computers. 192.168.1.1 is the first number of this range, so the router often reserves this number by default. Users can often enter this number in a browser when connected to the network to configure the router.