I am not entirely sure what a performance test is, but I can help with the others. A polygraph is a machine, used usually if you are in legal trouble, to see if you are lying. While results aren't 100% accurate, you typically can get a gage for if someone committed a crime. They are also rarely used for interviews, some companies want to see if people are lying on their resumes. Drug tests are tests that are given to most people with a job, and especially sports players. Companies especially like to test people for drugs, to see if they might be on an illegal drug that could cause them to work less efficiently. It also is a liability issue for the company if an employee is on an illegal drug. Drug tests are typically done at a lab, and you usually have to pee in a cup and have it get tested.