Bit-depth

Bit-depth refers to how many distinct colors you can see on your monitor. As stated previously, how many colors you can see on your monitor is directly proportional to how much VRAM or DRAM you have on your video card. Below is a chart for determining how much VRAM or DRAM you need installed on your video card to see a given number of colors at standard resolutions.

Note that the RAM requirements given are not exact, but are shown in the amounts that are most common for purchase.

**Chart for Determining VRAM Requirements**
	16 colors (4-bit)	256 colors (8-bit)	32,768 colors (15-bit)	65,536 colors (16-bit)	16.7 million colors (24-bit)
640x480	256k	512k	1MB	1MB	1MB
800x600	256k	512k	1MB	1MB	2MB
832x624	512k	1MB	1MB	2MB	2MB
1024x768	512k	2MB	2MB	4MB	4MB
1152x870	512k	2MB	2MB	4MB	4MB
1280x1024	1MB	2MB	4MB	4MB	8MB
1360x1024	1MB	2MB	4MB	4MB	8MB
1600x1200	1MB	2MB	4MB	4MB	8MB

The main point I'm trying to get across from this chart is: the higher the resolution and the more colors you need to see, the greater the amount of Video RAM you need installed on your video card.

Of course even if your monitor and video card will enable you to see millions of colors, if your image is only comprised of 256 colors (such as the maximum amount of colors in a GIF image), then you will only be able to see the 256 colors the image has to offer and no more.