AI paradigms

The unsupervised learning is used for datasets whose items are not labeled and, therefore, our goal now is just to learn some patterns in the dataset. How do we train an unsupervised model? Using the same example as in supervised learning section, the cacti and Ryan Reynolds are now provided to the model without any label nor train or test split. The fact that the data are not labeled, "Unsupervised paradigm" means that we have no test set. If we have no test set we need to validate our model based on other methods like cluster cohesion.