A telephone is a communication tool that interfaces between two people engaged in conversation at one level. It also interfaces between each user and the communication network at another level. It is in the domain of media and communications technology that a counter-intuitive aspect of our relationships with our tools first began to gain popular recognition. Marshall McLuhan famously said "We shape our tools. And then our tools shape us." McLuhan was referring to the fact that our social practices co-evolve with our use of new tools and the refinements we make to existing tools.
In North American colloquialism, the word "tool" may be loosely used to describe an individual of low mental capacity (essentially, an "idiot") or someone who fails to realise that they are being taken advantage of by others. This metaphor is drawn from the understanding that tools (as understood by most of society) are objects that are used for specific tasks.
Read more about this topic: Toolcase