What is the purpose of a variable in programming?

The purpose of a variable in programming is to allow for data changes during execution. Variables act as containers that hold values which can be modified throughout the life of a program. This flexibility is essential because it enables programmers to create dynamic and responsive applications where data may change based on user input or other conditions.

When you define a variable, you can assign it a value, and as the program runs, that value can be updated as needed. For example, if you have a variable representing a user's score in a game, this value needs to change as the game progresses, reflecting the current state of play. This capability to store and update data is central to making software flexible and interactive.

While the other options are relevant concepts in programming, they do not accurately describe the core function of a variable. Storing constant values contradicts the nature of variables, as they are intended to hold changing data. Defining function parameters involves more specialized uses of variables, tied to how functions operate but does not encompass the entire purpose of variables. Enforcing immutability deals with values that cannot be changed once created, which is more applicable to constants or specific data structures rather than the general concept of variables in programming.