Digitizers convert analog or physical input into digital images by using a touch-sensitive scanning surface that sends signals to software. They emerged in the 1950s and have since become important tools for computer-aided design and converting hand drawings into digital formats like textures and animation. Modern digitizers come in different types, with features like resolution, sensitivity, and image recognition varying between tablet-style digitizers that use a stylus for input and more advanced digitizers that leverage lasers or camera pens.