Nick here from Shopify.
Shopify Payments is partnered with Stripe for a lot of the countries where Shopify Payments is available and the USA is one of these countries. Because of this, Shopify Payments is essentially Stripe but removes the transaction fee's for you also, which is a big bonus of using the gateway. It also means that you have Shopify in house support about anything to do with the gateway.
You can look into and see more information about Shopify Payments from the guide Shopify made about all things Shopify Payments here.
Hope this helps and answers your question!
All the best, Nick