Julie here from Shopify Support.
I appreciate you sharing that screenshot! However, because the screenshot doesn't show the entire product page, it's quite difficult to discern where it's coming from.
Are you noticing the same description on every product page? If so, this is likely something that you had set up within the Product pages section in your theme editor, which can be accessed by heading to Online store > Themes > Customize > Product pages. Whether this is the case depends on the theme you're using.
If you are only noticing this description on one of your product pages, on the other hand, then it sounds like what you're seeing is your product description. This can be edited by heading into Products and selecting the product in question. From there, you'll notice a Description section, which you can then edit.
Do you mind sharing a link to this product page? If you can also let me know which theme you're using, that would be helpful! This will help me get a better understanding of what's going on so I can further assist.
Looking forward to your response!