Daily Active Users (DAU)
DAU is a metric used to measure a digital product's user interaction with its product or service. DAU measures how many unique users visit a product on a daily basis. It is one of the metrics that is used to measure the success of a product. The higher the DAU, the more “sticky” your app/website is viewed as being by potential users. In order to calculate DAU, you first need to define a user and then determine what type of activity they're engaging in (consumption or engagement).
Design thinking is a relatively old methodology for designing. Design thinking gives a framework to solve the problems of users. In design thinking, there are steps to follow: empathize, define, ideate, prototype, and test.