Need help understanding UEFI while installing Windows 7 64 Ultimate

It's embarrassing to say how many hours I have invested in fighting the UEFI on my MB. Anyway, I need some help understanding how and why you should choose UEFI when installing Windows. Windows 7 in this particular case.

I'll try to start by explaining some of the issues and some of the parts of UEFI I don't understand. let's begin with my boot options that has had me pulling my hair out.

Asus bios boot options look something like this

1.DVD drive
2.SSD
3.HDD
4.UEFI DVD drive (this particular option has caused me some major headache and I don't understand its use. If I try to install windows 7 using the UEFI drive it will disable my mouse at the Windows 7 install screen.
5.Windows boot device. Can't remember the exact label on that but it is usually tied to my SSD booting ability

The way I finally got my install to go smooth was to only have the first 3 boot options available. Disabling 4 and 5

Also, in my bios I can choose between Windows UEFI or Other OS? Right now I'm using the windows UEFI choice, although I'm doubting I'm fully utilizing UEFI since I did not install my copy of with with UEFI DVD drive

I guess what I really want to know is how to use UEFI? What is it? Why should I use it? and last but not least what is that UEFI DVD drive, why is this a necessary boot option?

I'm currently reading through that thread you linked. It's a good chunk of info to digest.

Do you think a copy of Windows 10 would install With UEFi more smoothly. Or in other words, are UEFI and windows 10 more compatible to each other?

And does anyone know if UEFI creates issues when dual booting say an SSD and HDD...

Thanks a bunch ThrashZone!!! Your post lead me to this Intel Skylake Removes Support for USB based Windows 7 Installation - Major Platform Specs Confirmed

Now I know why my USB ports stop working during the windows 7 install with UEFI.