It is quite literally as easy as typing a friends name and having it auto completed. Typing in a number and hitting send.
Paypal might have an app that does something similar and it likely came after Venmo gained popularity. For most of us, who have been using Paypal since the 2000s, it might not seem logical, but Paypal UI experience does seem like an archaic UI experience by comparison even to me.
As of now, I don't disagree. PayPal has successfully adopted most of the best parts of Venmo (though time to receive money remains the slowest of all the competitors) and Square Cash is miles ahead of both of them - the ability to send money to people who don't have an account, and allowing them to access that money without creating an account is simply fantastic. No more conversations with friends like "Look, I'm sorry I don't have cash right now. You can wait, or you can download Venmo and let me pay you now."
I can easily search for a friend, and send them money right away. In addition, you can request money from people.
It's really easy to split groceries, utilities, and other bills with roommates and friends.