Excel offers you an ability to assign user-level permissions to different areas on a protected spreadsheet. You can specify which users can edit a particular range while the spreadsheet is protected. As an option, you can require a password to make changes.
With Excel built-in tools you can easily work together on workbooks and monitor who, when and what changes made. E.g., track project status and tasks.
Working with large and complex Excel workbooks, especially when entering large amounts of data, no one is protected from accidental changes in formulas, formats and other spreadsheet elements. But you can protect yourself from too much work on finding and eliminating such errors by protecting the individual spreadsheet elements.
You can significantly reduce the number of errors in data entry in Excel by protecting changes of specific spreadsheets (worksheets) and cells.
Sometimes it is necessary to compare two Excel worksheets. E.g., compare balance sheets for different periods of time. You can do it by comparing worksheets side by side in two automatically linked windows.
Color code is a perfect way to identify content and draw an attention to it. In Excel you can easily change colors of one or more spreadsheet tabs.
You can use Excel's AutoCorrect feature to create shortcuts for commonly used words or phrases.
Sometimes you might want to lock cells in your Excel spreadsheet that contain formulas and functions or data. Thus, the person doing the data entry will not accidentally overwrite or delete the spreadsheet formulas and functions or your data.
If you are working with huge workbooks that contain a very large number of formulas, functions, and data, you can turn off the automatic recalculation.