AutoIt is a freeware scripting language designed for automating windows GUI and general scripting. It uses a combination of mouse movement, keystrokes and window control manipulation to automate a task which is not possible by selenium web-driver.
Why Use AutoIt?
Selenium is an open source tool that is designed to automate web-based applications on different browsers but to handle window GUI and non HTML popups in application. AutoIT is required as these window based activity are not handled by Selenium.
Source: https://www.guru99.com/use-autoit-selenium.html
