At the product custom fields page you can enable or disable and setup the availability of custom fields for products and you can also manage your product custom field groups
Product custom fields are additional fields for product that appear alongside the default form fields for products.
With product custom fields you can add fields that are commonly used for certain products, to your administrator and vendor product forms at the product details pages.
These additional fields are also displayed at the storefront and are available for product comparison or for product filters, provided the specific options are enabled or selected.