The phrase "personalization settings" refers to the options or choices in a device or software that allow you to customize or adjust how it looks, behaves, or interacts with you, making it unique to your preferences and needs. Full definition
These settings are comprised of the Start screen, appearance, and desktop personalization settings. (howtogeek.com)
Windows 10 includes bunch of personalization settings that let you change your desktop background, windows colors, lock screen background, and more. (howtogeek.com)
In addition, the ability to toggle between Start menu and Start screen has been moved to the new Start settings page under Personalization settings. (blogs.windows.com)