If you want to be acquainted to the WEBGUI, then this post should help you a bit...
What is the WEBGUI?
It is one of the three GUIs provided by SAP: SAPGUI for Windows, SAPGUI for Java and SAPGUI for HTML (a.k.a. WEBGUI). Read SAP note 710719 for more details about the SAPGUI family.
Where is the WEBGUI?
It is present in all SAP Netweaver ABAP application servers, as of release 6.40; for lower releases, it was available through the ITS 6.20 (installed in a separate server). Nowadays the ITS 6.20 is out of support (SAP note 197746).
When use the WEBGUI?
When you want to use a web browser to execute an ABAP transaction code (might be embedded inside the Enterprise Portal, CRM, NWBC).
Why use the WEBGUI?
Because it is a GUI that you do not need to install. Just use your favorite web browser (as long as supported by the Product Availability Matrix) and have fun! Ok, there are limitations too: SAP Note 314568 presents the list.
The WEBGUI service is available via the ITS (Internet Transaction Server).
Ok, what comes next? Issues involving ITS and WEBGUI (look for my other blog post)!