In software testing, what does the term 'response time' primarily refer to?

The term 'response time' in software testing primarily refers to the duration needed to process a transaction. This metric is crucial because it measures how quickly the system responds to a user’s request or a specific transaction. A fast response time can significantly enhance user experience, indicating that the application is efficient and effectively handles user requests.

In performance testing, understanding response time helps in evaluating the system's performance under various conditions and loads. It provides insights into how well the system operates in real-world scenarios, ultimately guiding developers to make necessary adjustments to optimize performance.

The other options do not align with the definition of response time: the time taken to complete a test run is more about the overall testing process rather than the speed of individual transactions. The waiting time for user interaction typically involves delays before the user can act rather than how quickly the system processes after an action has been taken. The overall time spent on testing encompasses the entire testing cycle rather than focusing specifically on the response during transactions.