What is the primary distinction between global and local variables?

The primary distinction between global and local variables lies in their scope of accessibility within a program. Global variables are declared outside of any function and can be accessed from any part of the program, meaning any function can use them once they have been defined. This allows for shared data across multiple functions, which can be useful in managing state or configuration throughout a program's execution.

In contrast, local variables are defined within a specific function and can only be accessed within that function. They exist in memory only while the function is executing, and once the function completes, those variables are no longer available. This encapsulation is vital for creating modular code, as it helps prevent unintended interactions between different parts of the program.

Thus, the correct answer emphasizes that global variables have a broader reach across the program, while local variables are confined to their specific function context, highlighting the fundamental differences in their scope and lifetime.