what is the difference between internal and external fertilisation?

Internal fertilization is the process when the combining of male and female body occurs inside the body of the female after the process of copulation. In internal fertilization, the released gamete count will be lees compared to external fertilization. eg., fish, amphibians, algae etc. In case of external fertilization, this process of combining takes place outside the human body. Here, a large number of gametes are released as there are risk factors in achieving fertilization. eg. mammals, reptiles, birds, bryophytes etc.