The data who value does not change or remains fixed is called _____________.

Constant

Explanation:

Definition: A constant is a data item whose value does not change during the program's execution; it remains fixed and unaltered. This is in contrast to a variable, which can have its value modified during program execution.

Characteristics of Constants:

• Immutable: Once defined, the value cannot be changed.
• Enhances code readability and maintainability by providing meaningful names to fixed values.
• Allows for compile-time and run-time checks to ensure constancy assumptions are not violated.

Conclusion: In programming, a constant is a value which does not change during the execution of a program. It is essential for defining fixed values that should remain unaltered, enhancing code reliability and readability.