Automated software testing is the best way to increase the effectiveness, efficiency and coverage of your software testing. Every software development group tests its products, yet delivered software always has defects.
Test engineers strive to catch them before the product is released but they always creep in and they often reappear, even with the best manual testing processes.
An automated software testing tool is able to playback pre-recorded and predefined actions compare the results to the expected behavior and report the success or failure of these manual tests to a test engineer.
Once automated tests are created they can easily be repeated and they can be extended to perform tasks impossible with manual testing. Because of this, savvy managers have found that automated software testing is an essential component of successful development projects.
Manual software testing is performed by a human sitting in front of a computer carefully going through application screens, trying various usage and input combinations, comparing the results to the expected behavior and recording their observations/issues if any identified.
Manual tests are repeated often during development cycles for source code changes and other situations like multiple operating environments and hardware configurations.