What is the difference between individualization and specificity? This is P. E but they don't have that option

The principle of individualization is that no two people are the same. ... The principle of specificity is that exercising a certain body part or a particular skill primarily develops that part or skill.

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.