What is the goal of unsupervised machine learning?

Unsupervised Learning

Unsupervised learning is one of the main branches of machine learning.

Here I argue that unlike the other branches of machine learning (supervised and reinforcement learning), unsupervised learning is a rather heterogenous field that can serve several different goals.

It seems futile to try to define one single goal for unsupervised learning.

I identify four different goals for unsupervised learning:

1. Estimating the distribution
2. Generating new data points
3. Extracting features for downstream tasks
4. Understanding the data