What is WDR (Wide Dynamic Range) for Surveillance Cameras?

Cameras typically have limited range in the range of darkness to brightness that they are able to capture in a single image. In many conditions this can result in darker or brighter areas having no detail, where shadows become large areas of black or highlights become a large sea of white. Wide Dynamic Range is a feature of many cameras that allows a wider range of bright and dark detail to be captured, restoring detail in areas of underexposed shadows or overexposed highlights.