Machine Learning is a subset of Artificial Intelligence, which focuses on computer algorithms that can learn through data and through experiences.
The aim of a machine learning algorithm is to construct a model based on some training data, and then be able to make predictions on unseen data. In other words, computers are made to perform tasks without being explicitly programmed to do so.
Examples of machine learning include email spam filtering and computer vision.
The three broad categories into which machine learning approaches can be divided into are supervised learning, unsupervised learning, and reinforcement learning.
Supervised learning is when the computer is given some inputs and an output, and has to learn the function which maps the inputs to the output.
Unsupervised learning is when the computer has to find structure in the input as it is given no labels.
Reinforcement learning is when a computer is placed into an environment and whilst navigating the space or interacting with the environment, has to maximise the reward.