What is the difference between a variable and a constant in programming?

In programming, a variable is a storage location that can hold different values throughout the execution of a program. This characteristic of being able to change its value when needed is a fundamental aspect of how variables work, making them versatile and useful for handling dynamic data.

On the other hand, a constant is a value that, once assigned, does not change during the execution of the program. Constants provide a way to name fixed values and ensure that they remain unchanged, which can be helpful for maintaining the integrity of certain data throughout the program, such as defining fixed mathematical values (like pi) or configuration settings.

This distinction between the mutability of variables and the immutability of constants is essential for effective programming, allowing developers to clearly define which pieces of data are subject to change and which are intended to remain constant.