"The iOS system is based on the same technologies used by Mac OS X, namely the Mach kernel and BSD interfaces. Thus, iOS apps run in a UNIX-based system and hav

"The iOS system is based on the same technologies used by Mac OS X, namely the Mach kernel and BSD interfaces. Thus, iOS apps run in a UNIX-based system and have full support for threads, sockets, and many of the other technologies typically available at that level."[1] [1]: https://developer.apple.com/library/ios/documentation/iphone/conceptual/iphoneosprogrammingguide/TheiOSEnvironment/TheiOSEnvironment.html https://developer.apple.com/library/ios/documentation/iphone...