There are different ways to edit a page title.  We will go over which page titles there are and how to change them.

The Product Page Titles are controlled by the Products themselves.  See more info here.

You can also create a custom title for the Product details page.  See more below.

There are Category Page Titles. See more here.

Then there are "page" titles.  For pages that do not have to do with Products or Ads.  Those are edited in the "Page Settings" area of each page.

See screenshot:

Product Details Page SEO settings:

YourDomain.com > Modules > Ecommerce: Products (mX) > General Settings

You can create a page title based on the combined fields listed above.  In this scenario the page title for a  product will show the "Name"(the field "name" in the Product) and an underscore "_" then the "SKU" field,  then the "Discounted Price" field will display in the page title.

see screenshot:

In the example above you have the "Name" (Cover alls) and Underscore "_" then the SKU (10009) and Discounted price ($55.00) show pushed to gether because there is nothing specified to separate them.