Scrotum is a sac like structure that encloses the testes.
The testes, after development in the abdominal cavity, descends into the scrotal sac after child birth.
Function:
Scrotum maintains the developed sperm at a temperature which is lower than the normal body temperature helping restore their viability. Sperms are sensitive to high temperatures.
The contraction of the scrotal skin pulls the testes closer to the abdomen during winters so as to keep them warm.
The loosening of the scrotal skin helps in the descent of the scrotum preventing them from excessive heat exposure during summers.