An Overview of OS X and How It Operates
Apple's OS X, previously known as Mac OS X, is a Unix-based operating system developed, marketed, and sold exclusively by Apple Inc. OS X only runs on Mac computers, and it has been that way since 2002 when it was released. Mac OS has been Apple's operating system on computers since 1984, with periodic updates released every year. The 'X' in OS X is a large part of its brand identity, used to emphasize how closely related OS X and UNIX are. All versions of OS X are named after big cats. For example, the current version, 10.9, is called "Mavericks", and previous versions have been called "Mountain Lion", "Lion", "Snow Leopard", "Leopard", "Tiger", "Panther", "Jaguar", "Puma", and "Cheetah". Mac OS X 10.7 "Lion" was the first operating system Apple developed to exclusively support 64-bit CPUs, whereas previous versions also supported 32-bit Intel processors.
OS X has a complicated anatomy. At the heart of the operating system is the XNU kernel (the part of OS X that loads first). This kernel controls and monitors all of the hardware resources of the computer such as memory, processor allocation, and disk drives. The kernel also controls device drivers, which allows external devices to interact with the computer. Finally, the kernel monitors and maintains system securities and permissions. Below the kernel layer of OS 10 are the core services and application services layers. These layers form a stack. At the bottom of this stack is the hardware and firmware, and above it is where the operating system kernel is. The final two layers of the stack are the core services and the application services.
Mac OS X is a computer operating system that supports multi-touch gestures. This doesn't mean that a touch monitor is required. A Mac computer with either a touchpad or Magic Mouse can execute commands via touch or motion. Another feature of OS X is the ability to use apps and play games that are also available on iOS, Apple's mobile operating system. One unique feature to OS X is the ability of the user to change a computer's IP address, if desired. An IP address is a unique address, similar to an identity, on the internet. Features Mac OS X share with iOS include applications for photos, music, Maps, FaceTime (video and audio call capabilities without using the mobile network), Safari (iOS's browser), AirDrop (a data sharing application), Game Center, and AirPlay (a program to wirelessly stream from the phone to a television via Apple TV).