You have to know commands, command syntax and generally know the different levels of software, what they do and how, and how to optimize and troubleshoot them. Each half has 50 questions and you are given an hour for each test. If you know what you are doing, it shouldn't take nearly that long. Next, you are expected to collect a few manufacturer 'certs'. They usually take anywhere from 3 hours to three days to cover the material and then you are tested.
Some courses provide their own testing right in the course.
Most others require being tested through Sylvan Prometric Testing Centers . Upon successfully passing the exam, you are given access to the manufacturer's warranty support for that product or product line. Many of the manufacturers require a minimum number of certified techs at a specfic client that is based on the number of machines from that manufacturer on the site. Often, these certifications are associated with your company and not necessarily you personally. In other words, the cert is good for you while you are working for that service company.