A machine learning model is an algorithmic structure that, based on input data, makes predictions or decisions, identifying patterns or making decisions with minimal human intervention. These models can range from simple linear regression to complex neural networks. They are trained on a set of data (training dataset) to learn from the properties of the data and then used to make predictions on new, unseen data. Machine learning models have a wide range of applications, including image and speech recognition, medical diagnosis, stock market trading, and battery performance prediction.