When you refer to a particular figure in your document, rather than typing in “Figure 12, page 43”, you can have Word manage it automatically by using a cross-reference. This means that if the figure number or page location changes, the in-text reference will also change.
You must be using the Insert Caption tool to create your captions for cross-references to Figures/Tables/Equations/etc... to work. If you'll be cross-referencing chapters and sections within chapters, then you must be using Heading Styles.
As an example of how the Cross-reference tool works, here's how to use it to cross-reference a figure:
When your caption number changes, you can update the in-text references by right-clicking the in-text reference and selecting Update field.
What if you want to refer to multiple items, as in (Figures 1, 2, and 4), or (Figs. 5-6)?
You can do this by modifying the Field Codes, which are the normally-hidden codes controlling what's displayed in the cross-reference.
First off, go ahead and insert the cross-references for each. Then:
There's not really a way to handle "Figures 5-10"...since figures 6, 7, 8, 9 aren't displayed, so there's nothing to click on if you want to jump to one of those.
This gets into some geeky stuff...
When you insert a cross-reference to a figure as we've described above, Word will insert "Figure X". But there may be an expectation in your discipline that parenthetical references like this should refer to "Fig. X". We can't hack Word to get it to automatically do that exactly, but we can get it to leave off the word "Figure", giving us a chance to type in "Fig." ourselves.
After you insert a cross-reference (this is similar to what we talked about in the section above):
Yes, you'll have to do that with each individual cross-reference.