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While this is better in terms of SEO, the ability for indexes to scroll your site, and for users to understand what their address bar is while they’re moving through your site, if there are places online where that initial url is still shown, it will render a 404 errors when you push your site live on UltraCart. A 404 error simply means that the indexes do not have that page and therefore it cannot be rendered for you. The continued use of this constitutes not only people not being able to get where they want to by clicking a link, but it also causes the search engines to dock you points.
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The other is the redirect mapping that is done when you first change your site over this . This would be in the form of a redirect shown here:
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