When working with Excel (Word, PowerPoint), you can mark your work as final and read-only for other people. No one can change them because all the typing, editing, and proofing commands are turned off. Marking as final is not a security feature, but a feature allows you to focus on reading. Please check how to protect a worksheet and follow steps below to mark it.
Step 1: Click the "File" Tab from the Ribbon;
Step 2: Click Info from the left navigation sidebar;
Step 3: Click Protect Workbook, then select "Mark as Final";
Step 4: A notice will appear "This workbook will be marked as final and then saved";
Step 5: Click OK, and browse to find the place to save the Excel;
Step 6: Click Save, another notice will appear. At the same time, the Mark as Final icon displays in the Status bar;
Step 7: A status bar appears on the top.