IS SAP GUI a relational database?

[ACF1]

Hello, 

I am a job seeker and trying to add data entry into SAP on my resume, but I cannot seem to find a straight answer on whether or not SAP GUI is a relational database system or not. 
Any help in clarifying would be greatly appreciated and if I need to add anything to help provide enough context I will gladly do so. 

Thank you for your time

[Sandra_Rossi]

It looks more like an interview question. If you don't know what SAP GUI is or what RDBMS is, don't indicate anything about it.

[mamartins]

SAP R/3 or S/4HANA architecture is called a 3-Tier: Database + Application Server + Presentation Layer (click to maximize):

The SAP GUI sits on the presentation layer. There other clients, like the WEB GUI, the Business Client, ...

More info here: https://community.sap.com/t5/application-development-discussions/sap-architecture/td-p/12562428