What is the Difference Between Classification and Regression?

Classification is used to produce discrete results, classification is used to classify data into some specific categories.
For example, classifying emails into spam and non-spam categories.

Whereas, regression deals with continuous data.
For example, predicting stock prices at a certain point in time.

Classification is used to predict the output into a group of classes.
For example, Is it Hot or Cold tomorrow?

Whereas, regression is used to predict the relationship that data represents.
For example, What is the temperature tomorrow?