Basket Analysis is a modelling technique based upon the theory that if you buy a certain group of items, you are more (or less) likely to buy another group of items. For example, if a couple aged between 25 and 35 buys some apparel for their own need, they will surely buy something for age group between 0 and 5.

The set of items a customer buys is referred to as an itemset, and market basket analysis seeks to find relationships between purchases.

Traditionally, the relationship will be in the form of a rule

The Customer here is a parent and will surely buy some articles for their kids. This is referred to as the support for the rule. The conditional probability that a customer will purchase kids articles is referred to as the confidence.