ATAR stands for the Australian Tertiary Admission Rank. It is a percentile ranking from 0.00 to 99.95 that indicates a student's academic position relative to all other students in their age group in Australia. The ATAR is used by universities and other tertiary education institutions as a primary criterion to select and admit students into their courses. It essentially ranks students based on their overall academic performance in Year 12, with a higher ATAR meaning better performance compared to peers. For example, an ATAR of 90 means a student performed better than 90% of their cohort. The ATAR is not a score or grade out of 100 but a ranking, and is designed to allow fair comparison among students regardless of the subjects they have studied.