What type of variable is defined for set values that remain unchanged throughout the execution of a program?

The correct answer is a constant variable. A constant variable is defined to hold values that are fixed and do not change during the execution of a program. This means that once a constant is assigned a value, that value remains the same and cannot be altered by any operation or action within the program.

Using constant variables is essential for maintaining integrity in coding where specific values should remain unchanged, which helps prevent accidental modifications that could lead to bugs or unintended side effects in the program. For example, constants can represent important values like mathematical constants (like π) or configuration settings that should remain consistent across the execution of the program.

Understanding constant variables helps in reinforcing the idea of immutability in programming, ensuring that certain data points are preserved, which is a key principle in many programming environments.