Have you ever wondered how Amazon and Flipkart recommend products to you? How can Gmail distinguish between spam and non-spam emails? How does Netflix anticipate your favourite shows? How do they manage to accomplish it? These are a handful of the questions we sometimes contemplate. In reality, such jobs are difficult to do without access to data. Data science is all about using data to solve problems. The problem could be decision making such as identifying which email is spam and which is not. Or a product recommendation such as which movie to watch? Or predicting the outcome in future So, the core job of a data scientist is to understand the data, extract useful information out of it and apply this in solving the problems.