It is used to dictate which Shopify product is linked to the current div/section.
This component is used by Looop to find the add-to-cart button, quantity input, options selector, and subscription selector related to the product.

looopid is the Shopify ID of the product. This can be assessed using the dynamic value for the custom attribute in element setting in Webflow designer.
On product page we will use the section as product card, and will place all ecommerce related elements inside the product card.
For collection lists we will use the Webflow Collection Item as the product card, and will place all ecommerce related elements inside the product card.
For collection lists we will use the Webflow Collection Item as the product card, and will place all ecommerce related elements inside the product card.