Originally Answered: What does 'Purpose' mean?
From Wikipedia (*): "Purpose is the reason for an action being done, an object existing or being made or used. Purpose can be synonymous with the goal or the intended result of an action."
Taking this definition apart explicitly, the word is used in three senses:
One, requiring a cognizant being with a value system who predicts (rightly or wrongly) the various outcomes of different actions that it could take, and based on the predictions, chooses to take an action which will result in a later situation with a higher value for that being.
Second, the perceived function of literary device or other artistic symbol, or of a tool. "This hammer's purpose is to drive nails in." Or "the purpose of the long earlobes on the statue of the Buddha is to represent wisdom." etc. Essentially, then, it is a means to emphasize either a logical implication or a causal effect.
Third, determination. "He acted with purpose."
Now, whether you have a purpose has several answers. First, in your job, you could be considered a tool for an end. Or your girl- or boy-friend may be using you to make someone jealous. Or, if you believe in supernatural or mystical beings with volition who control you, you could have a purpose for that being. Or people -- or you -- may believe this to be the case, so that you believe yourself to have this purpose and act accordingly, thereby making yourself a tool of your own belief. (This is the way that existentialism recommends that you give yourself a purpose if you decide to continue living.)
You have this purpose because of the volition and power, or of an interpretation, of others who see you as a means to an end.
You are given this purpose either by those who thus use you or by those who interpret you as being a means to an end.