What is PayPal USD on Coinbase?

Could you please elaborate on what "PayPal USD" specifically refers to on the Coinbase platform? Is it a direct integration that allows users to deposit and withdraw funds from their PayPal accounts in US dollars? Or is it a virtual currency or token representing the value of the US dollar? I'm curious to understand if there's a direct partnership between PayPal and Coinbase for this service and what the benefits or limitations might be for users looking to leverage this feature. Clarifying these points would greatly assist in understanding the true nature and functionality of "PayPal USD" on Coinbase.