How do we understand each other? What role does the word play in this? What is required for a word to become full of meaning, i.e. “alive”, helping to understand and experience what it points to or hints at? The purpose of this book is to show that the main thing is what lies BEHIND THE WORD in personal and social experience (without this, the sequence of sounds or graphemes remains “dead”). The interface theory of meaning provides an explanation of the double life of the word and reveals the mediating role of meaning in two positions: (I) between society and the individual; (II) between a discrete linguistic unit and what lies behind the word in the internal context - a hologram of the individual’s image of the world as a result of the processing of verbal and non-verbal experience of cognition and communication. The book is useful for a wide range of readers interested in issues of knowledge of the world, communication, mutual understanding, adaptation to the current situation, language acquisition, etc.