How does a constant differ from a variable?

A constant is defined as a value that remains unchanged throughout the execution of a program or during its entire lifespan. This characteristic distinguishes it from a variable, which is designed to hold data that can be altered at any point during the program's execution. Because constants do not vary, they can be utilized for values that the developer intends to remain static, providing clarity and reliability in the code.

In contrast, variables are meant to hold data that may vary as the program runs, allowing for dynamic changes. Understanding this distinction between constants and variables is key in programming as it impacts how data is managed and how algorithms are structured. By using constants, developers can prevent unintended alterations to specific values, leading to more stable and predictable behavior in their applications.