the defination of machine learing
Arthur Samuel:the field of study that gives computers the ability to learn without being explicitly programmed.
Tom Mitchell: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.
Machine learning algorithms:
Supervised learning:To predict the result by analyzing some correct relationship between the input and the output.
"regression":we are trying to predict results within a continuous output.
"classification": we are instead trying to predict results in a discrete output.
Unsupervised learning:To approach problems with little or no idea what our results should look like.