Hello,
I'm an independent advisor that Microsoft asked to assist customers. I'm an experienced user of Office but do not speak for Microsoft. I've been assisting my fellow users for more than 20 years. I hope I can help you.
The anchor tells you where Word things your object is, roughly. It will be anchored to a particular paragraph usually. If that paragraph gets moved to a new page because of changes in the document, the object will move with that paragraph. Generally, you want the anchor close to where you want the object.
If you move your object far enough, the anchor will move as well.
See: https://wordmvp.com/FAQs/DrwGrphcs/Anchors.htm for more about how anchors work and more generally about how Word handles drawings, see:
https://wordmvp.com/FAQs/DrawingGraphics.htm
I hope this information helps. Please let me know if you have any more questions or require further help. .
Regards