This thesis is focused on creating Web applications and services using the programming language C# and the Microsoft development environment Visual Studio 2010. This paper is divided into three chapters. The first one examines the ASP.NET technologies for the development of Web applications and services. It provides insight into the areas currently used in ASP.NET. In addition to this, it presents the development of versions, functions and components of this technology. The second chapter deals with the properties and use of Web services. The instructions for creating simple Web services and services for complex mathematical operations follow. Its functions are used by the console clients and the clients with user interface. The third chapt...