What is Machine learning ?

Machine Learning is the Field of study that gives computers the ability to learn without being explicitly programmed - by Arthur Samuel

A computer program is said to learn from experience E with respect to some task T and some performance measure P, if its performance on T, as measured by P, improves with experience E”

Modelling

Its simply a specification of a mathematical ( or probabilistic) relationship that exists between different variables.

ax1 + bx2 + c = y

Where x1 and x2 are input variables and y is output variable 

Machine Learning is used for creating and using models that are learned from data.

Examples

• Predicting credit default risk.
• Sentiment analysis.
• Recognize a character from a plain image( also known as OCR).
• Human activity recognition using mobile sensor data.
• Packet routing across routers and switches.
• Predicting someone’s income from their click through information.

Real world examples

• Email classification as spam email or not a spam email in outlook, Gmail, yahoo etc.
• Google News feed.
• Google’s Driverless Cars
• Amazon’s Product Recommender System’s.