When you create a page or article on your website, you should have a title, description and a preview image uploaded for social media. Once a link to that page is posted on a social network, such as Facebook, Linkedin or Twitter, then that platform will scan it and remember the information associated with that link.
But what if you change the details on the page or post later? If you change the title of the page, or even the description and image, then social networks won't immediately recognise it. This means that if anyone re-shares the link, the original page details will be displayed.
This problem resolves itself after a few days on the social network end, which updates the data itself. But if you don't want to wait, you can use the manual update on each of the social networks.
All these services make it easy to keep your social media content up to date.