A conflict happens when two users are both editing the same shared workbook and try to save changes that affect the same cell. Excel can keep only one of the changes in that cell. When the second user saves the workbook, Excel displays the Resolve Conflicts dialog box to that user.
In the Resolve Conflicts dialog box, read the information about each change and the conflicting changes made by the other user.
To keep your change or the other user's change and to advance to the next conflicting change, click Accept Mine or Accept Other.
To keep all of your remaining changes or all of the other user's changes, click Accept All Mine or Accept All Others.
To have your changes override all other changes without displaying the Resolve Conflicts dialog box again, do the following:
On the Review tab, in the Changes group, click Share Workbook.
On the Advanced tab, under Conflicting changes between users, click The changes being saved win, and then click OK.
To view how you or others resolved past conflicts, do the following:
On the Review tab, in the Changes group, click Track Changes, and then click Highlight Changes.
In the When list, select All.
Clear the Who and Where check boxes.
Select the List changes on a new sheet check box, and then click OK.
On the History worksheet, scroll to the right to view the Action Type and Losing Action columns.