Every product or service release or upgrade needs the team to ensure that the product or service functions the way it is supposed to. The extent to which the product or service meets the needs of its customer represents its quality, which is a collective responsibility of the team. One of the ways to ensure quality is through verification through testing. A person who is dedicated to complete testing and verification on the whole or a part of the product is generally known as the Tester or Quality Analyst.
A tester or quality analyst may perform various types of testing, on various fronts to ensure quality. Some examples are - functional testing, load testing, performance testing, security testing etc.