The different types of machine learning models include Supervised Learning (e.g., linear regression, logistic regression, support vector machines, decision trees), Unsupervised Learning (e.g., k-means clustering, hierarchical clustering, Principal Component Analysis), Semi-Supervised Learning, and Reinforcement Learning. Apart from these, Deep Learning models like Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs) and Generative Adversarial Networks (GANs) are also widely used.