Exploring synthetic users
Most of the systems we test have some concept of a user and a login. That isn’t true for everything. Sometimes, systems are more like an online brochure or desktop application. Still, most software that is complex enough to warrant a book on testing has some sort of log-in concept. The purpose of having separate users includes isolating what that user can see as well as presenting custom and user-created content. That could be a list of orders, a shopping cart, credit card information, emails sent and received, public social media messages published, or the ability to scroll through messages published by others the user has access to.
This means User’s have unique views into the system. They might create some combination of data that no one else can see. If by some miracle they report the problem without advanced tools, it is unlikely that it will be easy to reproduce. In addition, testers may wish to see things as users do in the live system...