What role do commit messages play in version control?

Commit messages are fundamental in version control systems because they provide context and detail regarding the changes made in each commit. By capturing the thought process behind a change, commit messages help developers understand the history of the project. This historical tracking enables team members to follow the evolution of the codebase, making it easier to identify when specific changes were made and why they were implemented.

With clear and informative commit messages, teams can quickly assess the purpose and impact of past modifications, facilitating better collaboration and project management. This organizational aspect of commit messages is what makes option B the correct choice, as tracking the history of changes enhances the overall clarity and maintainability of the project.

The other options highlight interesting aspects of version control but do not capture the primary role of commit messages. For example, while commit messages may implicitly indicate the time of the change, the primary function is more about documenting the change itself rather than the time it occurred. Commit messages do not represent changes in file format or store backup copies of files either; these functions are addressed by the version control system in different ways.