What is a global variable?

A global variable is indeed a variable that is declared outside of all functions, making it accessible from any function within the same program. This means that any function can read or modify the value of the global variable, which can be beneficial for sharing data across different parts of the program. By having such a variable, it facilitates communication between functions without needing to pass the variable as an argument.

This accessibility is what distinguishes global variables from local variables, which are only visible within the function they are declared. This scope consideration is crucial in programming for managing data and ensuring any function can utilize the global state as needed.

The concept of global variables can lead to easier data management in some cases; however, it can also introduce challenges related to maintaining state and debugging, as any part of the program can alter the global state. Therefore, understanding the implications of using global variables is essential for effective coding practices.