I need educated... Please help

I have no clue when it comes to tweaking options on my video card. That goes for D3D and OpenGL!!!
I have a Creativelabs Anniholator 2 and am using the Nvidia 22.50 drivers on a P3 700mhz. I also use the GTU tweaker from guru3d as well.
I have no clue what is better to use. OpenGL or D3D??? I don’t know which is the newer technology or if any of that realy matters.
If soeone could help me out with definitions of terms or tell me what I should turn on or off with my card it would be appreciated.
Maybe a good link would help.
Thanxxx for your time.

Cylon Zephrim: Leader of the Cylonian Empire

General speaking is OpenGL and Direct3D equal but certain program+driver combinations works better with one of them. Just try both.
I would put the screen in 32 bit color depth and skip the tweaking.

Thanxxx Broken Rubber for taking the time to answer my post.
I get low bench marks with the mad onion 2001 program and the DroneZ benchmarker. Thought tweaking would help. But I don’t know what half the stuff is. I’ll put my res. into 32 bit.
Thanxxx

Cylon Zephrim: Leader of the Cylonian Empire