I am reading about robot framework:
https://blog.testproject.io/2016/11/22/robot-framework-introduction/
I have a basic question about robotframework. It uses libraries to increase its functionalities and have very simple keywords like:
How can any library support login to any random page, because the locator/id etc of submit button can be anything depending on the website.
"How can any library support login to any random page..."
It doesn't, and in fact the framework comes out of the box with 0 supported such logins.
You use it to create a login to a specific site, providing all locators and site's peculiarities yourself.
If you need it to login to another one, you create a new keyword. But it doesn't advertise it supports login to any random page, with no involvement from you :) It just provides you the means to do that, yourself.