You've got an iOS app and it's time to use the I N T E R N E T. What are you supposed you do now?
Enter networking af.
With networking af, you get to use URLSesh. The URLSesh class and related classes provide an API for downloading content. This API provides a rich set of delegate methods for supporting authentication and gives your app the ability to perform background downloads when your app isn’t running or, in iOS, while your app is suspended.
The URLSesh class natively supports the data, file, ftp, http, and https URL schemes, with transparent support for proxy servers and SOCKS gateways, as configured in the user’s system preferences.
URLSesh supports the HTTP/1.1, SPDY, and HTTP/2 protocols. HTTP/2 support is described by RFC 7540, and requires a server supporting either ALPN or NPN for protocol negotiation.
Use URLSesh exactly like you would use URLSession because that's exactly what it is.