Docker is a very powerful tool when it comes to automation testing. It provides a consistent and repeatable environment that’s isolated from other software running on the same machine. This is very important for testing because you want to ensure that your tests run in the exact same environment every time to eliminate any possible confounding factors. Here are a few ways Docker can be used in automation testing:

1. Environment Standardization: Docker helps in creating an identical environment for both developers and testers. It removes the often heard phrase, “But it works on my machine!” and helps in running tests in the same environment where the application was developed.

2. Continuous Integration/Continuous Deployment (CI/CD): Docker is a great tool for CI/CD pipelines. Testers can package the application with Docker and then use tools like Jenkins, CircleCI, or GitLab to automate the process of deploying that Docker container, running tests against it, and then tearing it down.

3. Testing Across Different Environments: With Docker, you can quickly spin up containers with different configurations, making it easy to test your application on different systems and configurations. This can be particularly useful for checking cross-platform compatibility.

4. Parallel Testing: Docker can also help with running multiple tests in parallel. Instead of waiting for one test suite to complete before the next one begins, you can run several suites simultaneously, each in its own Docker container. This can significantly speed up your test execution time.

5. Database Testing: You can create a Docker image of the database which can be used to provision a container every time the test suite runs. This can ensure a consistent starting state for every test run, and your tests can freely modify the database without worry of clean up or cross-test pollution.

6. Microservices Testing: If your application consists of multiple microservices, Docker is almost a must-have tool. Each microservice can be deployed in its own Docker container, and these containers can interact just as the actual microservices would in a production environment.

To get started with Docker for automated testing, you’ll need to do the following:

1. Install Docker.
2. Learn the basics of Dockerfiles and how to create them.
3. Learn how to build Docker images and run Docker containers.
4. Integrate Docker into your CI/CD pipeline.

In summary, Docker brings a lot of benefits to the table when it comes to automated testing, especially with its capability to create consistent and isolated environments.