Standard Dynamic Range (SDR) refers to the traditional way of encoding and displaying images and videos, with a limited range of brightness and color. SDR is characterized by having a limited contrast ratio, which is the difference between the brightest and darkest parts of an image, and a limited color gamut, which is the range of colors that can be represented.
Most older displays and standard definition televisions use SDR technology, while newer displays often use High Dynamic Range (HDR), which offers a wider range of brightness, contrast, and color compared to SDR. The move towards HDR has been driven by the increasing demand for more immersive and realistic visual experiences in areas such as gaming, home entertainment, and digital cinema.