With the popularity of Continuous Integration and Continuous Delivery practices, automated testing is gaining an increased slice of the overall testing specification. This is no surprise, since automated tests provide great benefits over manual testing. It makes the testing process faster, systematic (thus avoiding errors), and reduces the effort associated with the execution and validation.
Automated tests are implemented as code, either compiled or not. Usually, they are executed during the Continuous Integration process, triggered by code changes or on a timely basis.