ICSI is an intra-cytoplasmic sperm injection and is basically a way to fertilize an egg with sperm by directly injecting it into an egg using a micro-pipette. After ICSI the resulting zygote (or embryo) is made to culture in the laboratory inside an incubator which simulates the intrauterine environment. Usually, the embryo(s) made thereof are transferred inside the uterine cavity (womb) at three or five days of culture inside the incubator. GIFT on the other hand is gamete intrafallopian transfer and it involves putting both eggs (single or a few in number) and sperms simultaneously inside the Fallopian tube and not the uterus. Here, it is thought that since both gametes are close to each other they will fertilize on their own and they are not fertilized outside the body. After fertilization the resulting embryo(s) will travel and implant inside the womb at about the 5th or 6th day of life, just like it happens in a natural conception.