3. The Kernel

The kernel has the task of:

• Loading / Unloading applications from memory
• Scheduling tasks to run efficiently on the CPU
• Memory management
• File storage to and from secondary storage devices such as the hard disk
• File management
• Data security

The kernel within each different type of operating system is responsible for a slightly different blend of tasks.

For example, a 'single user, single application' operating system does not have to deal with networking, whereas the kernel in a network operating system would be responsible for this.

Because memory is such a limited resource on mobile phones, their operating systems require a more efficient memory management kernel as opposed to those running on PCs.