Photoresist is a light-sensitive material used in the process of photolithography, which is essential in semiconductor manufacturing. It allows for the precise transfer of patterns onto surfaces, such as silicon wafers, by changing its chemical properties when exposed to light. After exposure, the photoresist can be developed to remove either the exposed or unexposed areas, depending on whether it is a positive or negative type. This process creates intricate designs that are crucial for the production of electronic components, including microchips and circuit boards.