You first have to understand that Word is *not* a drawing program - it's a
*word* processor which happens to provide some [rather nice] drawing tools.
The next significant concept is a bit more difficult for some to grasp
:
There is no such thing as a physical page in a Word document. Therefore any
graphic element (or other object) has to be "attached" to [and moves with]
the text in one of two ways:
1- In Line With Text, which means it is treated as any other character in a
line of the text, or
2- Floating, which means it can be positioned as you wish but still remains
anchored to a paragraph - even if that paragraph has no other content.
You might have a look at the following article as well as some of the
included links - such as the one pertaining to "About floating graphics".
http://word.mvps.org/Mac/PagesInWord.html