Router IP addresses which are also router gateway addresses that allow network admin to login and manage network settings as long as router configuration, including WiFi setup, network security, network filtering and so on.
Most router brands such as Netgear, Linksys, TP-link, Asus use 192.168.1.1 or 192.168.0.1 as their default login IP address, it makes router management really simple and easy for users. But some other router models do not use IP but URL as login address, it varies from brand to model, you need to find router IP address correctly.
In the following list you could find most default router IP address or URL. Choose one and you will get more information.