Google Shopping is a service that allows merchants to list their products by uploading a product feed in the Merchant Center.
Judge.me recommends Google Shopping For Shopify: The Definitive Guide for learning all aspects of Google Shopping.
Read more about Google Shopping on the Shopify Blog: What is Google Shopping and How Does it Work?
In order to show products on Google Shopping, product data has to be uploaded to Google Shopping via the Merchant Center in the form of a product feed (Primary feed).
We currently recommend two apps for creating the product feed: