K-nearest neighbor is a supervised clustering algorithm. Can be used for classification and regression problems.
Example of a trivial classification problem: based on the age of the subject, determines if one like pineapple on his pizza:
The output (label) of a classification algorithm is typically represented as an integer number such as 1, -1, or 0
Example of a trivial regression problem: predict the weight of a person given their height:
Output of a regression problem is a real number

