One of the selling points of a web framework like ASP.NET Core is the ability to provide a dynamic app, customized to individual users. Many apps have the concept of an “account” with the service, which you can “sign in” to and get a different experience.
Depending on the service, an account gives you varying things: on some apps you may have to sign in to get access to additional features, and on others you might see suggested articles. On an e-commerce app, you’d be able to place orders and view your past orders; on Stack Overflow you can post questions and answers; whereas on a news site you might get a customized experience based on previous articles you’ve viewed.