Normal distribution.
Musselwhite, D., & Wesolowski, B. (2018). Normal distribution. In B. B. Frey (Ed.), The SAGE encyclopedia of educational research, measurement, and evaluation (pp. 1155-1157). SAGE.
The normal distribution represents the distribution of scores in a sample that is obtained from a population. While the majority of scores are in the middle of the distribution, as scores move away from the middle, the frequencies decrease.