Both are of 2 types but are different from each other
Sterility – Primary: When a couple has not been able to conceive after a year of unprotected intercourse.
Secondary: When after having a child, a couple has not been able to conceive another pregnancy after unprotected intercourse for 2-3 years.
Infertility – Primary: When a couple conceives but has not been able to maintain a pregnancy for long (till childbirth).
Infertility – Secondary: When a couple after first successful pregnancy and labor, has not been able to maintain a second pregnancy for long.