If your question is "why is word the core of anu language."
The reason that words are the core of any language is that a need to communicate with others was a going and growing concern. Since the dawn of mankind we needed to share our thoughts and trade; from cave paintings to ancient manuscripts, the need to communicate has always been there.
As technology came into our lives and new products and services were created so was more words and definitions; so to answer your question, words are and will remain the core of any language as a vehicle of communication.
I hope I understood your question correctly and answered your question, otherwise this has been a mis interpretation of the core of the question.