File Input/Output (I/O) refers to the process of reading data from and writing data to files on a computer. This allows programs to store information permanently or retrieve it later. For example, a program can read a text file to display its contents or write user data to a file for future use. In programming, file I/O is essential for managing data efficiently. Different programming languages, such as Python or Java, provide built-in functions to handle file operations. These functions enable developers to open, close, read, and write files, making it easier to work with large amounts of data.