The Data Mining Forum (v2)

I have this question. It seems to me That clustering Is very similar to classification. What Is the difference?

From my understanding, clustering is about automatically grouping together objects based on their attributes, when we dont know the groups beforehand.

Classification is about determining to which group (class) an object belong given some predefined groups and information about some objets in those groups

For clustering, some popular algorithms are DBSCAN, the K-MEANS, and the DENSITY PEAK CLUSTERING. Some new algorithms now also use the deep learning etc.

For classification, the popular algorithms are like ID3, C4.5, KNN, Decision tree, SVM, deep learning, Extreme learning machine etc.