A quick search on google or wikipedia could give u an anwser.
They both make hardware BUT in order for hardware to function properly, u need drivers.
Drivers = a sort of software.
PS: ATI was bought by AMD
wikipedia wrote:
ATI Technologies Inc. was a major designer and supplier of graphics processing units, motherboard chipsets, and video display cards. In 2006, the company was acquired by Advanced Micro Devices, although the ATI brand was retained for certain products.
http://en.wikipedia.org/wiki/ATI_Technologieshttp://www.nvidia.com/page/home.htmlhttp://ati.amd.com/support/driver.html-----------------
chickenfeather wrote:
They are companies that make the chips that go on your graphics card.
Not only graphics card, but they are most known for them