This is known as a standardised score and it often corresponds to a ‘normed’ score. The T-Score scale ranges from approximately 10-90 along a normal distribution. Individuals with a T-Score of 50 are said to be at the 50th percentile which means they have done better (or worse) than 50% of people who have taken that assessment previously (norm group).
This scale is often used for ability assessments. It is also easy to combine the T-scores of two assessments such as Verbal and Numerical reasoning tests to provide a summarised ability score which can then be ranked to choose the best individuals from an applicant pool.