With anonymous testing, the clinic has no way to identify you as an individual. When you come in for testing you are assigned a number, and you use that same number to receive your results. Your name is never associated with your test results, and you are the only person who knows what they are.
In contrast, with confidential testing, although your results are kept private, your name is associated with them, and they may be released to your insurance company, health care provider, or even the state or local government. Before being tested, you should always ask who will have access to your results.

