Yes, it updates all the links, if you do it when the book opens or you click
the UPDATE LINKS option in the EDIT > LINKS window.
If you connect values in a cell to a cell from another sheet using a FORMULA
instead of a link, then those links may update constantly and individually as
the remote sheet is update...unless you've set the sheet to manual
calculation. In that case you would have to press F9 to get those formulaic
links to update.
Does that cover your question?