What Is the Language?

When our teacher asked to us: “What is language?” I couldn’t give a specific answer,because the language means many things.So,my mind was bombarded by lots of things.I said to myself: “Language is our identity,language is our culture,language is words,rules,interfaces,signs,reaction,action,verbal,non-verbal,discourse...”I was confused by that attack of the opinions and couldn’t choose a specific word that identifies language for the teacher’s question.After the class,when I came to home on the bus,I thought and said to myself “Language is everything or everything is language.First of all,our teacher’s question is a language because she gives us an understandable action and expects from us a meaningful reaction.So,I can say that sending a meaningful message and taking an reasonable answer is the language and in the linguistics,it is called communication or interfaces.By this way,I can say that language conveys the meaning . So,language is the conveyor of the knowledge.”
Then I came to home.When I entered into home, I said to my friends “Hello,how are you” One of my friends said to me “ Hey,I was waiting for you.I have several questions about English.”(I want to give you a few details about my housemates.We are three friends at home and both of them try to learn English.)He asked to me several questions about the grammar and words.I answered them with pleasure because teaching something to somebody gives me pleasure.And then I said to him in English: “Every language has its own rules and words”He said: “What?I don’t understand you man. I said: “Don’t care.This is just the answer of my question.”
After then,when I sat and tried to write this paper.I remembered the persons who unable to speak.They can not speak verbally but they understand and communicate with each other by the sign language.So,language is not just a way of the producing sounds,it is a way of the understanding each other.
Is language thought?To me,it is not.Imagine that you are thinking but just