Just for you to understand what these articles are about: the BSP application...
The BSP application is one of the forms / shapes that is displayed the end user as Internet page via the "browser" (e.g. Internet Explorer). To enable communication/control over the HTML page, the page can support "Flow logic" which is covered in ABAP coding.
Thus: when you have an ITS (Internet Transaction Server) running, your end user can visit an URL which calls a BSP service. An HTML document with (potentially) SAP information on it can be shown and the user's response can be passed on back to SAP. Along with the BSP application, several "pages" and "mime-object" (e.g. pictures) can be made available.
Your SAP application will show up like a stand-alone web-site, which could be available from any computer over the world. User authentication is done automatically, unless the BSP application is started as anonymous application (where the user ID would be held against a guest user).