no predefined data set given to the machine the agent does all the work from scratch the next parameter to consider is training in supervised learning the training phase is well defined and very explicit the machine is fed training data where both the input and output is labeled and the only thing the algorithm has to do is map the input to the output so the training data act like a teacher or a guide over here now once the algorithm is well trained it is tested using the new data when it comes to unsupervised learning the training phase