Color depth (also known as bit depth) is one of the properties of photos and video that is discussed less often than marquee features like resolution, but it has a deep impact on the quality and appearance of your work. If you are new to photo and video work, check out this great video tutorial that will show you everything you need to know about color depth.
Coming to you from Saurav Sinha, this excellent video tutorial will show you the ins and outs of color depth. Color depth is a measure of how much data your camera can store in each color channel for each pixel. For example, when an image or video is recorded in 8-bit depth, each pixel will have 8 bits of data (a 0 or a 1) for each color channel (red, green, and blue). As such, each channel can record 2^8=256 different values, and the total number of colors are (2^8)^3=16,777,216. When it comes to image quality, higher bit depths are always better, as they allow for finer gradations of colors, which results in better accuracy and smoother transitions across the image, plus a lot more latitude in post-processing. One thing worth noting is that JPEG is 8-bit, which is one of the principal reasons why you should shoot in raw, which is typically 12-, 14-, or 16-bit. Check out the video above for the full rundown from Sinha.