What does the command "return 0;" signify in a C++ program?

The command "return 0;" in a C++ program indicates that the program has finished executing successfully. In C++, the return statement is used to exit a function and return a value. When the main function returns 0, it communicates to the operating system that the program completed without any errors. This is a standard convention in C and C++ programming, where a return value of zero signifies success, while any non-zero return value typically indicates an error or an abnormal termination of the program. Understanding this distinction is crucial for effective error handling and resource management in software development.