Communication is both a complex matter and a universal phenomenon. A sender, a receiver, and the information to be transferred form the essential elements. Communication takes place between humans, between animals, and between plants, but also between humans and animals, as well as between animals and plants. The information to be transformed takes many forms — visual, acoustic, olfactory, and tactile. In science, communication takes place as a rule in rather condensed forms, often visual as a written text; information may even be still more condensed as in a mathematical formula, in bar codes, or in digitized images. In theory, communication in the sciences should be precise and unequivocal, but in real life many ambiguities exist, some of them by coincidence and some deliberately introduced and the source of much confusion. A large number of dictionaries have been published to try to clarify scientific terminology and to ease communication.