Two ideas sit under every video image: color spaces, which define how colors are represented as numbers, and gamma, which defines how those numbers map to brightness on a screen. Understanding both explains why the same video can look different in different tools, and why color management exists at all.
Color spaces and RGB
When light hits a camera sensor, it is captured as three channels: red, green, and blue. Nearly all digital color starts from those three values. A color space is the standardized model that says exactly what each RGB combination means, because the same three numbers can represent visibly different colors on different devices. sRGB and Rec. 709 are two widely used reference color spaces in video and display work; they give tools a shared language for color.
Luma and chroma
Video signals are often separated into luma, the brightness information, and chroma, the color information. In YUV-style systems, Y carries luma while U and V, or Cb and Cr, carry color. This split matters because human vision is more sensitive to brightness detail than to color detail, and many video formats use that fact to compress color information more aggressively than brightness.
Gamma correction
Gamma correction is a nonlinear adjustment applied so that encoded values map to brightness the way human eyes expect. Vision is roughly logarithmic: we distinguish small differences in dark areas more readily than in bright ones. Without gamma correction, dark regions would look crushed and bright regions blown out. The correction spreads the values so a display shows a natural-looking range of brightness.
Bit depth per channel
Bit depth sets how finely each channel is measured. 8-bit video gives each channel 256 possible levels, which is enough for most viewing but can show banding in smooth gradients. 10-bit gives 1024 levels per channel, a common choice in professional editing and high dynamic range work where subtle gradations matter.
Why color management matters
Moving video between tools means moving numbers between color spaces. Color management is the practice of tracking and converting those spaces so the image looks as intended on each display. It ties together everything above: the space the pixels live in, the gamma that shapes their brightness, and the bit depth that limits their precision.