Photoresists are light-sensitive materials used in the process of photolithography, which is essential in the manufacturing of electronic components like semiconductors. When exposed to light, photoresists undergo a chemical change that allows them to either become soluble or insoluble in a developer solution, depending on whether they are positive or negative photoresists. After exposure and development, the remaining photoresist forms a pattern that acts as a mask for etching or depositing materials onto a substrate. This process is crucial for creating intricate circuits and structures on silicon wafers, enabling the production of modern electronic devices.