Local Variable vs. Global Variable — What's the Difference?

A "Local Variable" is a variable defined within a specific context or scope, such as within a function, method, or block of code. It is called "local" because it is only accessible and meaningful within that particular scope. Local variables have limited visibility and cannot be directly accessed from outside the scope in which they are defined. This characteristic ensures that the variable's value does not interfere with other parts of the program.

On the other hand, a "Global Variable" is a variable that is defined at the top level of a program, outside of any specific function or block. Global variables have broader accessibility and can be accessed from any part of the program, including within functions and blocks. They maintain their value throughout the program's execution and can be useful for storing information that needs to be shared across different parts of the code.

The primary difference lies in their scope. Local variables are confined to the scope in which they are declared, making them suitable for storing temporary or function-specific data. In contrast, global variables are available globally, allowing them to hold values accessible by various functions or modules within the program.

Local variables are typically used for short-term storage within functions, helping maintain data encapsulation and prevent unintended side effects. Global variables are employed when data needs to be shared across multiple functions, but their use should be minimized to maintain code clarity and avoid potential issues caused by global state changes.