Using the Open Graph (OG) Settings allows you to control what content is specifically published to social platforms, specifically:
While pasting your page URL into a social media site will still publish an image and text, it may not display the image and text you want without these already being defined in the Open Graph settings.
Where to find your settings
The Open Graph settings can be found under the page settings popup, or simply clicking the icon highlighted in purple below.
The title of your social media post
The description that will appear in your social media post
The image thumb that will display in your social media post
What is the Open Graph protocol?
"The Open Graph protocol enables any web page to become a rich object in a social graph. For instance, this is used on Facebook to allow any web page to have the same functionality as any other object on Facebook.
While many different technologies and schemas exist and could be combined together, there isn't a single technology which provides enough information to richly represent any web page within the social graph. The Open Graph protocol builds on these existing technologies and gives developers one thing to implement. Developer simplicity is a key goal of the Open Graph protocol which has informed many of the technical design decisions."
More can be found here which is the source of the above definition.