Track Changes turned on.
You are reviewing a document for your manager before it's sent to your entire organization. You see changes you want to make, which you want your manager to see. When you turn on Track Changes, Word inserts marks that show where deletions, insertions, and formatting changes are made.
On the Review tab, in the Tracking group, click Track Changes. The background of the Track Changes button changes color, which tells you it's on; any changes you make will be marked as revisions until you turn Track Changes off by clicking the button again.