audience in order to increase their number of purchases without being told "correctanswerunsupervised learning methods can look at complex data that is more expansive and seemingly unrelated in order to organize it in potentially meaningful ways unsupervised learning is often used for anomaly detection including for fraudulent credit card purchasesand recommender systems that recommend what products to buy next in unsupervised learninguntagged photos of dogs can be used as input data for the algorithm to find likenesses and classify dog photos together approaches as fieldmachine learning is closely related to computational statisticsso having background knowledge in statistics is useful for understanding and leveraging machine learning algorithms for those who may not have studied statisticsit can be helpful to first define correlation and regressionas they are commonly used techniques for investigating the relationship among quantitative variables correlation is measure of association between two variables that are not designated as either dependent or independent regression at basic level is used to examine the relationship between one dependent and one independent variable because regression statistics can be used to anticipate the dependent variable when the independent variable is knownregression enables prediction capabilities approaches to machine learning are continuously being developed for our purposeswe'll go through few of the popular approaches that are being used in machine learning at the time of writing