Selenium is primarily designed for functional and regression testing of web applications and is not typically used for performance testing. However, it can play a role in a broader performance testing strategy. Here’s how Selenium interacts with the domain of performance testing:

1. Functional Testing Focus: Selenium automates browsers to test the functionality of web applications, ensuring they work as expected. It’s not inherently equipped to measure the performance and load capacity of web applications.

2. Performance Testing Indirectly: While Selenium itself doesn’t measure performance metrics like response time, throughput, or resource utilization, it can be used in conjunction with performance testing tools. For example, Selenium scripts can replicate user interactions which can then be measured by a dedicated performance testing tool like Apache JMeter.

3. Load Testing Integration: Selenium can be integrated with tools like JMeter or LoadRunner for load testing. In this setup, Selenium handles the browser automation part, while the performance testing tool simulates multiple users and measures the application’s performance under load.

4. Identifying Performance Issues: Selenium can help in identifying certain types of performance issues. For example, if a web element takes too long to load or if there are functional issues under certain conditions, these can be indicators of underlying performance problems.

5. End-to-End Testing: In some cases, Selenium tests are part of broader end-to-end tests, where performance metrics might be gathered as part of a larger testing suite that includes Selenium.

6. Browser-Level Performance Testing: Selenium can be used to some extent for browser-level performance testing, like checking how long a page takes to load, or how quickly certain actions are completed in the browser. However, this is not the same as full application-level performance testing.