What is the purpose of the undo button in a spreadsheet?

The purpose of the undo button in a spreadsheet is to remove the last action performed. This functionality allows users to quickly correct mistakes or revert changes without having to manually reverse each step. For example, if a user accidentally deletes a cell's contents or incorrectly formats a range of cells, clicking the undo button will restore the previous state, making it a vital tool for improving efficiency and accuracy while working on spreadsheets. This feature helps maintain a smooth workflow, as users can experiment with data or formatting without fear of making irreversible changes.