Part 107 Test was an examination that first came into practice in August 2016. It is a requirement to clear this test for all those people who are looking to fly a drone commercially. Conducting under the aviation examination protocols set by US aviation and control, those applicants who clear the test get the license to fly the drone, and they can take the flight in the air according to the protocols that are standards and practices listed down under Part 107.
The test is not easy to pass, and you need to take a study course or go through the required material before you appear for the papers and qualify for the exams.
There are aeronautical training centers that offer the training courses and can teach you the basic course to help you clear the licensing exam and enable you to fly drones.