Language is the remarkable faculty by which humans convey thoughts to one another by means of a highly structured signal. Language works by two principles: a dictionary of memorized symbols, that is, words, and a set of generative rules organized into several subsystems, that is, grammar. The machinery of language appears to have been designed to encode and decode propositional information for the purpose of sharing it with others. Language is universally complex and develops reliably throughout the species, partly independently of general intelligence. I suggest that language is an adaptation for sharing information. It fits with many other features of our zoologically distinctive 'informavore' niche, in which people acquire, share and apply knowledge of how the world works to outsmart plants, animals and each other.