When you create a worksheet containing sensitive data or data you don’t want others to change, you can protect the sheet from being changed. To protect the sheets, go to the Review ribbon and click on the Protect Sheet option. From the protect sheet dialog box that appears you can select the actions that you want others to perform on the worksheet. You can also set a password to allow only those having the password to be able to work on the worksheet. You can also observe that the select cells options are checked by default which only allows others to select the cells, but does not permit to make any other changes such as deleting rows or columns, etc.
You can also increase the sheet protection by protecting individual cells. Excel allows you to lock cells, which stops others from editing or deleting any information in the selected cell. To lock cells, right click on the required cells, go to the protection tab and check on the required option. Please note that this change will not be effective until you turn on the sheet protection.