A standardized test is a test that is administered and scored in a consistent, or “standard”, manner. Standardized tests are designed in such a way that the questions, conditions for administering, scoring procedures, and interpretations are consistent and are administered and scored in a predetermined, standard manner.
Standardized tests do not need to be high-stakes tests, time-limited tests, or multiple-choice tests. The questions can be simple or complex. The subject matter among school-age students is frequently academic skills.
Standardized tests are perceived as being fairer than non-standardized tests, because everyone gets the same test and the same grading system. This is fairer and more objective than a system in which some students get an easier test and others get a more difficult test. The consistency also permits more reliable comparison of outcomes across all test takers, because everyone is taking the same test. (Wikipedia- Adjusted)