What is a variable in programming?

A variable in programming serves as a symbolic name for a value that can change during the execution of a program. This means that when you define a variable, you are essentially creating a reference to a specific memory location in which data can be stored and modified. The ability to change the value associated with a variable is crucial for dynamic programming, as it allows for the storage and manipulation of data as the program processes input or performs calculations.

In contrast, the other options are misrepresentations of what a variable is. A fixed name for a constant value implies the immutability of the variable, which contradicts its purpose. Similarly, a reserved keyword refers to predefined words in programming languages that have special significance and cannot be used as identifiers, which is different from what a variable does. Lastly, a variable is not a type of loop; loops perform iterations and control the flow of the program, whereas variables are used to store data that can be altered. Thus, identifying a variable correctly as a symbolic name for a value that can change is fundamental to understanding programming concepts.