Robot Versus Machine

People keep asking me this question all the time. Let me ask it here myself "What is the difference between a robot and a machine?"

At least we all know that a robot is definitely a machine but what is it that differentiates it from other machines?

I am sure there will be many answers to this questions and many of them would be better than the answer that I am going to give here. But in my opinion, a robot is a machine that exhibits certain aspect of sentient behaviour. Let me explain this.  When I say "sentient behaviour", I include the ability to make mistakes as well. So repeatability is not necessarily an important attribute of a robot. So while calculator is a machine it does not manifest any aspect of human behaviour, apart from the ability to compute with higher accuracy. 

Well it is very difficult to draw a very sharp line between a robot and a machine. But it is the behaviour which defines whether a machine is a robot or not. For instance, a camera in itself is a machine but a camera with a built-in face recognition algorithm may be considered as a robot. While machines are the extension of human faculties, robots exhibit behaviours.

To summarize, a machine may be called a robot if it has the following important attributes:

1. Autonomy: Ability to take decisions without human interference. 
2. Adaptibility: Ability to adapt to changes in the environment. 
3. Learning: It should be able to learn on its own and hence its behaviour should improve over time. 
4. Interact: Interact with other beings and with the environment. 

 These abilities may be available with a varying degree in different machines. In this aspect, we may safely say that a calculator is a simple machine and so is a motor cycle. However, a google car with autonomous navigation ability is a  robot and so is the roomba vacuum cleaner which can the clean the house on its own.