IVF and the concept of a test tube baby are interconnected terminologies describing the process of fertilizing an egg with sperm outside the body in a laboratory dish. IVF is a comprehensive fertility treatment that encompasses multiple steps, including ovarian stimulation, egg retrieval, fertilization, embryo culture, and embryo transfer. The term "test tube baby" is a more colloquial way of referring to a baby conceived through IVF. Despite the differences in terminology, both concepts describe the same fundamental process of assisted reproduction.