Bit depth refers to the number of bits used to represent the color of a single pixel in an image. A higher bit depth allows for more colors and finer gradations in tone, resulting in better image quality. For example, an image with a bit depth of 8 bits can display 256 colors, while a 16-bit image can show over 65,000 colors. In digital audio, bit depth affects the dynamic range of sound. A higher bit depth, such as 24 bits, captures more detail in the audio signal, allowing for a greater range between the quietest and loudest sounds. This is crucial for professional audio production and high-fidelity playback.