By definition, (graphical) user interface elements are those elements used by graphical user interfaces (GUIs) to offer a consistent visual language to represent information stored in computers. UI-elements not only represent information but also allow users to interact with the software. Common examples for UI-elements are windows, text fields, buttons, labels, lists, selection elements. Concerning automated software testing, the correct detection and identification of UI-elements of a tested software are important. Thus, the principles on which Ranorex Studio bases its UI-element detection is a fundamental concept which will be introduced compactly herein.