What does the 'VU' header represent in load testing?

The 'VU' header in load testing commonly stands for Virtual User ID. This identifier is instrumental in distinguishing between individual virtual users during a load test. Each virtual user simulates a real user interacting with the application under test, and assigning a unique ID to each one helps track their activities, performance metrics, and any potential issues that may arise during the testing process.

Having a Virtual User ID allows testers to analyze performance data accurately, as it associates specific requests and responses with the respective virtual users. This can be particularly useful when troubleshooting or optimizing application behavior under various load conditions since it helps link performance observations directly to individual user interactions.

Understanding the significance of the Virtual User ID in the context of load testing helps ensure comprehensive analysis and better insights into application performance during stress conditions.