Tracking the changes in documents

Hi all,

the scenario is: a document has been submitted for approval.

at the first step the approver (also having editing/ write rights in the documnt) makes some changes in the document, and approves the doc.

At the next step the i.e. 2nd approver, can there be any way by which we can show the changes made by the approver.

In short is there a way by which the changes in a document made by authors and approvers be tracked, so that at each step the approver knows who changed what? i DONT THINK vERSIONING CAN HELP HERE.

Hope I m clear, Kindly reply.