You can update your Product Meta Data when editing your product.

YourDomain.com > Modules > Ecommerce: Products (mX) > Products > Edit Product

Near the bottom of the "edit Product" screen.

The Page Title by Default (if Custom is not selected) uses the Product name_SKU.  Page Titles are important for SEO - NOTE:  THis is different than the page url.

Page Alias is created automatically for your products and uses the Name of the product to create it.  You create a custom alias by selecting "Custom" and specifying a name.  We do not recommend using spaces, but using an Underscore instead " _ "

Meta Description By default uses the Description text used in your Products description.  You can customize it by selecting "Custom" and writing something different there.

The Meta Description is what a Search Engine uses to briefly describe your item. (Most of the time - but not always.  Sometimes the SE shows content from the page - usually to show you where it found the text that you searched for)

Meta Keywords Are keywords search engines use to find your items.  By default this area is populated by the product name only.  It is a good idea to add more keywords that are relevant to your item. (things that people might use to describe this item when searching for it.)