Previously known as Product Listing Ads, Google Shopping is a comparison shopping feed or shopping engine that allows people to search, view and compare products. The products are shown whenever a potential customer searches through Google for an item from users who sell online. These can show up on the primary results page or in the shopping tab.
There are two platforms that power Google Shopping: Google Merchant Centre and AdWords. The Merchant Centre is where the product feed can be found which then links AdWords to the product listings of a website. Google Shopping can boost engagement rates as it lets products be listed above Google search results and AdWords.