IBM DevOps Test UI, also known as Rational Functional Tester, is a software tool designed for automated functional and regression testing of Graphical User Interfaces (GUIs) and data-driven testing. It automates the testing process to ensure application functionalities work as intended and identifies any issues caused by new code changes. The tool is tailored for GUI testing, allowing for easy recording and playback of test cases that interact with UI elements like buttons and menus. It supports data-driven testing, enabling comprehensive tests across various data sets. Additionally, it offers visual editing features with screenshot representations for easy test creation and ScriptAssure technology to maintain test scripts even if the UI changes.