What does resetting a router do?

Your ROUTER password and your NETWORK login are two different things. Your ROUTER password is the password you access your router with when you type in something like "192.168.1.1" into your browser. Your NETWORK login is the password you use when connecting to your ISP.

Resetting your ROUTER password will not change your ISP login.

Hope this was the answer to your question.

There are 2 types of resetting. Resetting is just rebooting or power cycling the router. Things are kept in a small piece of memory (NVRAM) so that the router remember those through the reset process.

Factory Default reset (often holding down a reset buttom) returns the router to a state from the factory. It will have all the factory defaults and firmware. You use this when you want to clear the router (you forgot the admin password) or if the router has somehow completely lost its mind with corrupt software.

Resetting a router will basically restore all of its settings to factory default. If you have configured any port-forwards or any settings configured, they would be erased. The system would set itself to exactly the way it was when you purchased it. (Passwords reset etc...)

When you ordered internet you give company passworg to go to your account online so you could check or pay yoyr bill etc.

When you reset router you don't change this password.Router just finds connected devices and gives them IP address.

Router password is different its not the same network password. You can search it in Google or you tube.