Unetbootin is a special tool that helps you make a special kind of memory stick called a "bootable USB drive". A bootable USB drive is a memory stick that can help you start up your computer using a special program or operating system, instead of just your normal operating system like Windows or MacOS.
So, let's imagine you want to install a new operating system, like Linux, on your computer. To do that, you need to download the Linux installation files, and then copy them onto a bootable USB drive. But making a bootable USB drive is not as easy as just copying the files onto the drive like you would with any other normal file.
That's where Unetbootin comes in! Unetbootin helps you make the bootable USB drive by doing all the complicated steps for you. It will automatically adjust the files and make the USB drive work properly with the operating system that you want to install.
Once you finish using Unetbootin and the bootable USB drive is ready, you can plug it into your computer, reboot it, and change the boot order to boot from the USB drive instead of your normal operating system. This will help you start up the computer using the operating system installed on the USB drive, and you can continue with the installation process.
In short, Unetbootin is a tool that helps you create a special memory stick that can help you start up your computer using a different operating system, making it useful for tasks like installing new operating systems or booting from a system rescue disk.