i am a new owner of 2008 mazda 3S. what is the use of media in the car stereo? can i use it as ipod connector?

Yes. that is what it was made for. There should be an ipod connector in the back compartment of the center console

You can use it for that, or you can use it with anything that has that jack (2.5mm stereo plug l think). You can use a MP3 player, old walkman cassette player, even an 8 track player if you have a portable one.

It is for your aux jack in the center console. You press media when you want whatever is plugged into your aux jack to come through the speakers.