Sort of, but Shopify (at least last I checked) is only the storefront and credit card processing. Warehousing, inventory management, fulfillment, and shipping are all 100% still on the vendor.

EDIT: Looks like Shopify is indeed setting up its own fulfillment network, but it was only announced a few months ago and is likely some ways off from launching:

https://www.bloomberg.com/news/articles/2019-06-19/shopify-s...