The Mac hardly invented networking -- Novell's NetWare disk-sharing tech debuted the year before the Mac, for example -- but the Mac made networking easy, something that took the PC years to duplicate. The secret was AppleTalk's peer-to-peer protocol that lets Macs and devices like printers communicate practically without configuration over Apple's proprietary LocalTalk connectors.
AppleTalk wasn't a clean protocol, so network admins hated its network chattiness. As Internet Protocol and Ethernet matured in the 1990s, Apple eventually dumped its own networking technologies, removing the last vestiges in 2012. But networking remains easier to this day on a Mac than on a PC, thanks to largely to 2002's zero-config Bonjour peer networking (which is also chatty, alas).