There are a few different ways to protect worksheets in Excel. One way is to use the Protect Sheet feature. To do this, go to the Review tab and click on Protect Sheet. A dialog box will appear where you can select which options to protect. For example, you can choose to protect cells, formulas, objects, and so on. Once you've selected the options you want, click OK. You will then be prompted to enter a password. This password will be required whenever someone tries to edit the protected parts of the worksheet.
Another way to protect worksheets is by using Share Workbook. With this method, multiple users can work on a workbook at the same time, but they will not be able to see each other's changes until the workbook is saved. To use this feature, go to the Review tab and click on Share Workbook. In the dialog box that appears, select the Advanced tab. Here, you can choose who can edit which parts of the workbook. Once you're done making your selections, click OK. Again, you will be prompted to enter a password.
Note: It is important to remember passwords for both of these methods, as there is no way to recover them if they are forgotten.