punch card

A punch card is a data storage medium used historically in computing and data processing. It consists of cards with rows and columns of small punched holes, each representing information in binary form. When holes are punched in specific positions, they encode data that a machine can read to perform tasks like data entry or program instructions. Think of it as a physical way to store digital information before modern digital storage devices. While largely obsolete today, punch cards played a significant role in early computing's development.