There is no difference between IVF and test tube babies. The term in vitro fertilization is a non-medical term used decades ago to refer to IVF or in vitro fertilization.
The term test tube baby comes from the conventional wisdom that embryos are formed in a test tube rather than in a woman's fallopian tubes. Indeed, eggs and sperm are fertilized in a petri dish. That is, they are fertilized in vitro in glass petri dishes, not in vivo
