I explain what is an unsupervised classification algorithm and what is a supervised algorithm. I use examples about remote sensing image classification and I discuss my opinion about the unsupervised algorithms, which are in fact similar to the supervised ones. Take as one example the well known unsupervised K-Means algorithm. The analyst must inform a priori the most important parameter to run the algorithm, the K value.I have a video about the K-Means algorithm.Follow my podcast: http://anchor.fm/tkortingSubscribe to my YouTube channel: http://youtube.com/tkortingThe intro and the final sounds were recorded at my home, using an old clock that belonged to my grandmother.Thanks for listening