1. The main page of a website is the home page which acts as a gateway to the rest of the pages of the website. The home page is usually the gateway to the website.

2. A home page is a webpage that serves as the starting point of a website.

3. This is the default webpage that loads when visiting a web address that contains only a domain name.

The main function of the operating system is to control both the hardware and software components of a computer. It acts as an intermediary, managing hardware resources and allowing software applications to run and interact with the computer's hardware. While organizing files and folders is a task performed by the operating system, its primary role is to facilitate communication between software and hardware, ensuring the computer functions properly.

Among the given statements about for loops, the one that is NOT true is that they are used to replace user input while loops. While for loops are typically used for iterations with a known count and are less likely to result in an infinite loop if used correctly, they do not specifically replace user input while loops.