I believe the answer would be the JPEG file extension.
Could you be more specific? So I can help you in the best way I can.
Answer:
Do this:
Position the insertion pointer where you want the index to appear. If you want the index to start on a new page, create a new page in Word. ...
Click the References tab.
In the Index group, click the Insert Index button. The Index dialog box appears. ...
Click the OK button to insert the index into your document.
