What is the purpose of a comment in source code?

A comment in source code serves the purpose of adding descriptions to the code. These comments are not executed as part of the program; instead, they provide context or explanations for others (or the original programmer at a later date) about what specific sections of the code do or why certain decisions were made during development.

This can greatly improve code readability and maintainability, especially in larger codebases where understanding the logic behind code can take time. While comments do not affect the execution of the program, they play a crucial role in communication between developers, making it easier to collaborate and debug.

Other options involve actions that do not align with the primary function of comments. Comments do not execute commands, declare variables, or enhance performance directly; they are purely informational. For these reasons, the purpose of a comment is best captured by the idea of adding descriptions to the source code.