SAP GUI : SAP Graphical User Interface enables the access to SAP/ ABAP-Systems like ERP
SAP NetWeaver Business Client : SAP NetWeaver Business Client (NWBC) is a new SAP user interface (UI), presenting end users with a seamless integration of classic SAP GUI-based transactions and newly developed applications based on Web Dynpro ABAP. In the desktop variant, a high-fidelity UI is offered to improve the user experience. NWBC provides the user with a typical, modern, desktop-based user experience.
SAPUI5 : HTML5 user interface, e.g. FIORI Apps…
SAP User-ID : P-User- (limited), S-User- (e.g. access to Notes) and Technical User Id.