Can anyone explain to me

Well I want to understand is Open gl a hardware or software thing, what I knew it was some kind of a software that a video card must support, what I need to know is if I buy a card that comes with open GL 1.4 can I use Apps that uses Open GL 2.0 is an GeForce 6200 LE core 350MHz Memory clock 532MHz(effective) 256 memory of 64bit gddr2.

for a i know: openGL is an API, same as directX
sort of collection of commands that can be executed very fast on certain hardware (GPU)
sort of an instruction set, for GPU-s and programmers

if you use a openGL 2.0 command on a openGL 1.4 supported card, the card will execute the command slower, than a openGL 1.4 or lower command.
like using directx9 on a directX8 card, everything directX8 or lower is executed fast by the hardware, directX9 commands aren't accelerated by hardware?

correct me if i'm wrong

I think I understaqnd you guys what you say is that open GL is a software thing but the hardware is what determines the performance of the card over the software like if the card with open GL 1.4 has only the minimum requeriments to support 2.0 and a card with full 2.0 support has the recomended requeriments on the GPU, Thanks a lot