What is Unsupervised Learning?

Now in unsupervised learning techniques,you don't have a known label with which to train the model.But you can still use an algorithm that finds similarities in data observations in order to group them into clusters.Suppose for example our health clinic has a website that contains links to articles and medical and healthy lifestyle publications. Now I might want to automatically group similar articles together Or maybe I want to segment our study participants, and we can categorize them based on similar characteristics. There are a number of ways we can create a clustering model. K means clustering is one of the most popular.