This is one of the most popular machine learning projects and can be used across different domains. You might be very familiar with a recommendation system if you've used any E-commerce site or Movie/Music website. In most E-commerce sites like Amazon, at the time of checkout, the system will recommend products that can be added to your cart. Similarly on Netflix or Spotify, based on the movies you have liked, it will show similar movies or songs that you may like. How does the system do this? This is a classic example where Machine Learning can be applied.