All includes the entirety of all the products you create, regardless of where they are saved.
Storage specifically contains products that are not saved to any Shopify or Etsy stores. You can save your products to be purchased or published at a later date here.
Shopify is where your Shopify stores are saved and where your Shopify products live for each one of your stores.
Etsy is where your Etsy stores are saved and where your Etsy products live for each one of your stores.