Machine learning and deep learning are the core techniques of data science that enable computers to learn from data and make predictions or decisions. You should have a good understanding of the principles and practices of machine learning and deep learning, such as supervised, unsupervised, and reinforcement learning, classification, regression, clustering, dimensionality reduction, feature engineering, model selection, validation, tuning, evaluation, and deployment. You should also be familiar with the most common machine learning and deep learning models and algorithms, such as linear models, decision trees, random forests, support vector machines, k-means, principal component analysis, neural networks, convolutional neural networks, recurrent neural networks, generative adversarial networks, and transformers. You should be able to explain how these models and algorithms work, what are their advantages and disadvantages, and how to use them for different data problems.