This article only applies to the old designer. Not sure which designer you have? Check here.
What is a page title?
A page title is the text that appears at the top of an internet browser when visiting a web page
How do I set a page title for one of my pages?
Step 1: Log in to the merchant portal, and navigate to the Design section
Step 2: On your published theme select Designer
Step 3: Click on the Settings button at the top of the designer
Step 4: In the settings dialog first select the page for which you want to change the title
Step 5: Change the value inside of the text box for Page Title
Step 6: Save the settings. Your page title is now changed!