What is the purpose of a variable in programming?

A variable in programming serves the fundamental purpose of storing data values that can be changed throughout the execution of a program. This capability allows programs to be dynamic and flexible, as variables can be updated or modified as needed during runtime. By assigning data to a variable, programmers can easily manipulate that data, perform calculations, and control the flow of the program based on user input or other runtime conditions.

For instance, consider a scenario where a program needs to keep track of a user's score in a game. A variable can hold the score value, and as the game progresses, this value can be incremented or decremented based on player actions. This functionality of adapting and storing different values is what makes variables truly essential in programming.

In contrast, defining the limits of a data set refers to characteristics associated with data structures or constants, which do not change during the execution of the program. Holding constant values throughout execution describes constants, which are different from variables as their values cannot be modified. Executing code repeatedly pertains to loops or control structures, which manage how many times certain code segments are to be run, but this is a separate concept from the purpose of a variable.