Both the Window Title and the Page Heading can be edited under Page > Metadata.
The Window Title will display in a few different places. It will display outside of the website's content area in the browser window as the title of the page. It is also what will be displayed in the search engine results page as the link for someone to click on when entering a page of a website. If you do any type of search at the search engine, look at the results that are returned; whatever you make the Window Title of you page is what will be displayed as the link to your page in this area.
The Page Heading is the text that will display in the banner image area.
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5-minute website fixes: How to change the window title of your business website