What is the primary purpose of a flow chart in programming?

A flow chart serves a vital role in programming by providing a visual representation of the sequence of operations that a program will follow. This graphical format allows programmers to outline the logic of their code in an easily understandable manner, illustrating how different decisions lead to various outcomes or actions within the program.

By using flow charts, developers can map out the control flow, identify potential loops, branches, and decision points, which helps in both the design and debugging processes. This visual tool aids in clarifying complex processes, ensuring that the logic is sound before diving into writing the actual code.

The other options pertain to unrelated aspects of programming and software development. For example, increasing file size is typically undesirable and not associated with flow charts, displaying error messages is more about runtime error handling than design, and encrypting program data pertains to security measures rather than visualizing program flow.