Excel offers two main ways to protect your data: protecting worksheets and protecting workbooks. Here's a breakdown of both methods:

Protecting Worksheets:

1. Select the worksheet: Click on the tab of the worksheet you want to protect.
2. Go to Review tab: Navigate to the "Review" tab on the Excel ribbon.
3. Protect Sheet: Click the button "Protect Sheet" within the "Changes" group.
4. Set permissions: A "Protect Sheet" dialog box will appear. Here, you can define what actions users are allowed to perform on the protected worksheet:
- Unchecked boxes: These actions are restricted (e.g., formatting cells, inserting rows/columns, deleting content).
- Checked boxes: These actions are allowed even with sheet protection (e.g., using formulas, selecting unlocked cells).
5. Password (Optional): While optional, it's highly recommended to set a password for unprotecting the worksheet. Enter your desired password in the "Password to unprotect sheet" box and retype it for confirmation.
6. Click OK: Click "OK" to activate sheet protection.

Protecting Workbooks:

1. Go to File Info: Click the "File" tab and then navigate to "Info."
2. Protect Workbook: Click the button "Protect Workbook" within the "Protect Workbook" section.
3. Choose a method: You have two options for workbook protection:
- Structure: This protects the overall structure of the workbook, preventing users from inserting or deleting sheets, hiding or unhiding sheets, and changing the workbook window layout.
- Encrypt with Password: This encrypts the entire workbook content with a password. Users won't be able to open the workbook at all without the correct password.
4. Set password (if applicable): If you choose "Structure" or "Encrypt with Password," a password prompt will appear. Enter your desired password and retype it for confirmation.
5. Click OK: Click "OK" to activate workbook protection.

Important Notes:

* Remember your password: Losing the password for sheet or workbook protection can be a hassle. Write down your passwords and store them securely, as Excel cannot recover them if forgotten.
* Granular control with worksheet protection: Worksheet protection offers more granular control over what users can and cannot do within the protected sheet.
* Workbook protection for structure and confidentiality: Workbook protection is useful for maintaining the workbook's overall structure or adding an extra layer of security with encryption.

By following these steps and understanding the differences between worksheet and workbook protection, you can effectively restrict editing and safeguard your valuable data in Excel.