Action bar is a container for primary and secondary actions related to the current screen or context within an application. Located typically at the top or bottom of the interface, the Action bar can contain elements like menu options, navigation buttons, title, or search field. Action bar content and layout can change based on the context, providing a dynamic way to interact with the app. It also maintains a consistent place for actions across different screens, aiding in usability and user learning. By centralizing primary actions and controls, the Action bar component enhances navigation efficiency and overall user experience.