Metafields sound technical, but with a bit of time they can be simple to understand. At the core, they’re about adding additional information into your admin or storefront that doesn’t come standard across Shopify’s platform. Many businesses have specific needs that are unique to what they sell, their customers and their business goals.
Read More Here:
https://www.shopify.com/au/partners/blog/made-with-metafields-part-1