Machine learning—a subfield of artificial intelligence that focuses on the study and development of models that learn from data—has played an important role in accelerating discovery in modern science. Fundamental concepts in machine learning including preprocessing, feature extraction, training, testing and validating learning models, overfitting and underfitting, performance evaluation, and phenomena associated with high-dimensional feature space are covered. Foundational machine learning models and algorithms including decision trees and random forests, support vector machines, and neural networks are described. Python code examples are provided as a companion tool for further explorations.