Nowadays, displaying onboarding screens to first-time users has become a common practice in mobile apps. The purpose of these onboarding screens — also referred to as walkthroughs — is to introduce the app and demonstrate what it does. Given that these are often the first set of screens with which users interact, they also set the users’ expectations of the app. Therefore, it is essential that those involved in creating the product — product managers, designers, developers — take the time to evaluate whether onboarding is necessary for the app and, if so, to determine the best way to implement it.

Read more on https://www.smashingmagazine.com/2014/08/mobile-onboarding-beginners-guide/