Introduction to Communication Theory/Semiotics
The literary theorist Kenneth Burke famously described human beings as "the symbol-making, symbol-using, symbol-misusing animal". Our broad use of symbols is a contrast from every species on earth. Only our closest relative, the Bonobo has shown any semblance of our symbol-using ability. It is the unique act of creating meaning out of arbitrary signs (be they vocalizations, gestures, or pictographs) that allows us to communicate an infinite range of concepts so fluently.
Through the Looking Glass, Chapter 6, by Lewis Carroll:
"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean -- neither more nor less."
"The question is," said Alice, "whether you can make words mean so many different things."
"The question is," said Humpty Dumpty, "which is to be master -- that's all."
Put in other words, put forth by different authors, "naming is the fundamental symbolic act".