How is mass selection different from individual?

In the case of mass selection from offspring, plants or animals with the necessary traits are taken and again they are crossed with each other, obtaining hybrids of the second generation. Among them, mass selection of individuals with the necessary traits is again made, etc. Mass selection is usually used for cross-pollinated plants and for animals.
In case of individual selection, a separate individual with a sign of interest to a person is selected and offspring are obtained from it. This method, of course, cannot be used in the selection of animals that reproduce sexually.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.