Drivers:Drivers are the link between the applicatin software 
	and the hardware and help them communicate. For a application
	developed using a specific api to work on a graphic card 
	there should be support for that api in the drivers of the card.
	These apis are regularly updated and new features are supported 
	by them so it is must that drivers also be regularly updated so 
	that newer features are supported and older compatibility 
	issues are resolved.Generally updated drivers are made avaliable 
	at the card manufactures website.Nowadays unified drivers are 
	made avaliable by card manufactures so that there is no confusion
	about choosing driver for your card.A good example of this is the
	Detonator driver from Nvidia which supports all its card from TNT
	to Geforce 256.

  Graphic accelerator:Normal 2D graphic card have just a
	DAC(Digital  to Analog signal Convertor) due to which they can 
	put the data  supplied to it on to the screen .Due to this they 
	are good enough  to run normal 2D applications but puts to much 
	load while running  3D applications.In a 3D accelerator card in 
	addtion to this	they  have a graphic processor .conventional 3D 
	graphic cards perform the task of processing graphic information 
	like creation of triangle (required to construct 3D images),
	scaling graphics, colouring them and using special effects like 
	alpha blending,	fogging,flat and gourand shading,mipmapping bi 
	and trilinear filtering to produde realistic looking graphics.

  Hardware transform and lighting:In conventional 3D graphic
        cards demanding jobs like moving the 3D object in 3D space and
        lighting the 3D scene are done by the CPU which has to perform
        other tasks like implementing physic ,artificial intelligence 
	etc.The lowers the overall performance .So newer cards like 
	Nvidia Geforce and its varients can them self perform transforms
	& lighting (moving the 3D polygons  with movement in the 3D 
	scene and lighting the 3D scene).This is a great performance 
	booster but the	problem is the application has to be 
	specifically written to take advantage of these features.

	
	

  Environmental Bumpmapping:This feature is supported by
	Matrox G400 /450 cards.BumpmappingIt is the process of adding 
	depth to the  textures to give a realistic look.In other cards 
	depth is given  only by shading(gourand shading) and generating 
	shadows, whereas in environmental bumpmapping actual ripples on 
	the surface are generated for example ripples on surface of 
	water or textures of sand.