This chapter, as does the remainder of the book, assumes a minimum familiarity with both ASP.NET Core and JavaScript basics. To learn about them, you may refer to Learning ASP.NET Core 2.0 (https://www.packtpub.com/application-development/javascript-and-jquery-7-days-video), and to Microsoft's official documentation (https://docs.microsoft.com/en-US/aspnet/core/?view=aspnetcore-2.1) for ASP.NET Core. Also, refer to JavaScript (and jQuery) in 7 Days (https://www.packtpub.com/application-development/javascript-and-jquery-7-days-video) to learn the basics of JavaScript and jQuery.
To learn more about TypeScript's design goals, please refer to the official design goals stated by the TypeScript development team: https://github.com/Microsoft/TypeScript/wiki/TypeScript-Design-Goals.