Sikuli is an open-source automation tool that uses image recognition to identify and control graphical user interface (GUI) elements. It allows users to automate repetitive tasks by taking screenshots of the elements they want to interact with, such as buttons or icons, and then writing scripts to perform actions like clicking or typing. The tool is particularly useful for automating tasks on applications that do not have a programmable interface. Sikuli supports various programming languages, including Python, making it accessible for both beginners and experienced developers looking to streamline their workflows.