The connection string is the link from the C# code to the physical database. The context must know where the database is located and how to authenticate to the database service. That information is usually stored in a string specific to an environment (development, testing, staging, or production). Each type of database service has a specific format for the connection string. ASP.NET provides a handy place to store strings like this. It is the file called appsettings.json. By convention the connection string will have the same name as the context class. We will make and explain the context class in an upcoming exercise.