Terminology means ‘a set of words used in a speciallyunderstood or defined sense’. From the standpoint of aninternational journal welcoming English language materialfrom all over the world, it is apparent that widespreaddifferences in meaning and uses of terminology exist in thefield of developmental medicine. Differences in terminologymatter, as Bax and Mac Keith commented, ‘First, foremost,surely, is how careful we must be in our language. If words areused... (that) confuse us they may in fact harm the patient’.