What is the primary function of the 'Undo' feature in Revit?

The primary function of the 'Undo' feature in Revit is to reverse the last action taken. This functionality allows users to step back through their previous actions, which is crucial for correcting mistakes or adjusting design choices without needing to manually redo or alter various components of the project. It streamlines the workflow by providing a quick way to fix errors, thus enhancing overall efficiency in the design process.

In the context of using Revit, every action taken—whether it's modifying a wall, moving an element, or changing a parameter—can be reverted with the 'Undo' command. This feature is especially useful in complex projects where changes can have cascading effects on other elements. In contrast, saving changes, deleting selected elements, or duplicating elements are entirely different functions that serve their own purposes within the software. Therefore, understanding the specific role of the 'Undo' function is critical for effective use of Revit in architectural design.