Parallel testing is a solution to speed up test execution time by running multiple tests simultaneously, allowing teams to decrease the time taken to run a test suite, increase coverage, and test continuously with more confidence. Nikolay Advolodkin introduces test parallelization using the Maven Surefire plugin, providing step-by-step guidance on implementing this best practice in production-ready code. By leveraging parallel testing, developers can achieve ultimate test automation results and improve their overall testing efficiency.