Until REST APIs came along, SOAP (Simple Object Access Protocol) was the de facto standard protocol on which web services were based. When working in ASP.Net Core, you might well encounter the ...

Take advantage of API key authentication to control the access of applications and services to your Web APIs in ASP.NET Core.

In ASP.NET Core, your web.config file with its <appsettings> section is gone. The replacement is a more extensive and configurable system that you can leverage to simplify configuring your objects.