What is the meaning of speech? The words? What types of speech are there?

Speech is the highest function of the nervous system, an important mechanism of intellectual activity, a form of communication between people and a way of transferring life experience. A word can be a symbol of a specific object or phenomenon; can serve as a generalizing, abstract concept; can replace signals from the outside world, directly affecting the senses; activates abstract and logical thinking, perception of signs and formulas.