File handling in C++ involves managing data stored in files on a computer’s storage system. C++ provides a set of classes and functions within its Standard Library (STL) to facilitate reading from and writing to files. The header offers ifstream (read), ofstream (write), and fstream (read and write) classes for this purpose.

To start, you open a file using the appropriate stream and perform read or write operations using stream extraction (>>) and insertion (<<) operators. Once done, you close the file to release resources.

File handling supports various operations like reading/writing line by line, binary file handling, random access, and error handling. It’s a fundamental feature for interacting with external data, often used in applications to store and retrieve information persistently.