Why use SPDIF?

I had the SPDIF port in my old Motherboard and never used it.

Now, with my new motherboard I again have that port.

Why do I need the SPDIF port if I have the regular headphone ports? Whats the diff.? is it better?

As americanau diophile indicated, SPDIF is a digital signal and cannot be use to a regular amplifier without a decoder. The SPDIF cable can carry up to 8 channels depending on the encoded signal.

Some amplified speakers has built-in decoding chips and therefore it can be connected using just one cable (coax or optical). Best uses of SPDIF is when watching movie or listening to music. Some games does not support multichannel through SPDIF therefore you will only get 2 channel signals. New type of coding called Dolby Digital Live may soon change that, as long as the programmers incorporate it on their design.

If you think about it the connection is only a device to transfer the signal from one end to another. You are less likely to lose much of the frequency through SPDIF than analog.

Analog and spdif at the same time is better than splitting it.

Yes, all you need to do is set the option on your device manager to have digital and analog output.