The iPhone is one of the few devices that has its very own operating system. This means that there is a maximization of the software-hardware compatibility. To create the most secure and efficient structure in the iOS (short for iPhone Operating System), the first developers decided to divide it in 4 layers that communicate only with the layer above and/or beneath it. This way for instance, they can make sure that the deepest layer, the “Core Layer”, cannot be changed by any event in the 2 upper layers.
This layer is very important for application developers, because it contains the key frameworks that provide the infrastructure you need to implement applications. It is vital to try and build your application only with the functions available in this layer.
2) Media Layer
When you develop a program that will need multimedia services, you have to address this layer. It contains all the graphics, audio and video technologies which will make it easier for you to build applications that look and sound great. It provides support for path-based drawing, anti-aliased rendering, gradients, images, colors, coordinate-space transformations, and PDF document creation, display, and parsing.
Core Services is the layer that provides the fundamental system services that all applications use. Even if you do not use these services directly, know that every technology in the system is built on top of them. There are many frameworks (Address Book, SQLLite …) located in this layer.
Core OS is the layer that encompasses the kernel environment, drivers, and basic interfaces of the operating system. The kernel itself is based on Mach and is responsible for every aspect of the operating system. It manages the virtual memory system, threads, file system, network, and interprocess communication. The drivers at this layer also provide the interface between the available hardware and system frameworks. However, access to the kernel and drivers is restricted to a limited set of system frameworks and applications for security purposes.
SPEC India is an ISO 9001:2008 certified Company serving the IT support and solutions sector since 1989. At SPEC India, we have a team of around 135 well-trained software professionals for iPhone apps development as well as mobile websites design and development. Our global Client and strong portfolio base proves our expertise in iPhone applications development.