Random Forrest

Random Forrest is an ensemble classifier (it can also be used as a regressor, instead of majority voting we consider the weighted average of each individual tree for the final outcome). It combines multiple decision tree classifiers to form a final single classifier. While decision trees are common and simple supervised learning method, they have some drawbacks as well, such as bias and overfitting. Such drawbacks can be overcome by using multiple decision trees to form an ensemble in the random forest algorithm. They improve the predictions, particularly when the individual trees are uncorrelated (random) with each other.

Unlike a single decision tree, random forrest selects a subset of features as well. This can reduce the risk of overfitting. Each individual tree predicts a output class, and the class gets majority voting is the model's prediction. Random forest algorithms have three main hyperparameters: node size, the number of trees, and the number of features sampled.