Irrlicht Engine

Ok I think I've been using these 3 words wrong.
Programmer does the code, little else.
Designer gives the people the "idea" of the game, and they make it so..
what's a developer? A mixture?
And as well, another myth I hear is designer!=programmer
I disagree. They can be both at times, so long as everyone's on the same page.
Someone help me understand this.
Thank you.

I am neither a designer, programmer, or developer but I model, program, and develop. I call myself an engineer xD.

I think developer is just a general term that covers all aspects of making a game (programming, art, design, etc). Designer can be used as a general term, but I'd rather be called a developer. Programmer usually just means coding, although a programmer can be a developer or designer.

game developer - covers the code side, scripts and the resources load into the engine (already made assets)
graphics designer - covers the art side - can be 2d, 3d, pixel, animator etc.
game designer - works on the game idea and logic and many other things non code and art related

I think there's quite a large amount of ambiguity on these terms (as you can see from the replies here)

I'd also go with saying that a developer can be any kind of team member, not only a software engineer

'Designer' is kind of a bad word these days in the indie and hobbyist development tracks, since a lot of 'idea guys' call themselves game designers (sites like gamedev.net are filled with these, just check out their 'Help Wanted' board), while an industry game designer is someone who needs an understanding of how games and game development cycles work
The designer(s) would be responsible of writing the GDD in such a way that both artists and engineers can understand it (which is a daunting task), and of setting the creative direction the game project should go in (and more)