The term machine learning was coined in 1959 by Arthur Samuel, an American pioneer in artificial intelligence. Tom M. Mitchell, an American computer scientist, provided a more formal definition of machine learning later:
A computer program is said to learn from experience E with respect to some class of tasks T and performance measure P if its performance at tasks in T, as measured by P, improves with experience E.
In simpler terms, this quote describes a computer program that has the ability to learn without being explicitly programmed. In machine learning, algorithms are used to build a mathematical model of sample data or training data. The models are used for computer programs to make predictions and decisions without being explicitly programmed for the task in question.