The critical code of the kernel is usually loaded into a separate area of memory, which is protected from access by application software or other less critical parts of the operating system. The kernel performs its tasks, such as running processes, managing hardware devices such as the hard disk, and handling interrupts, in this protected kernel space. In contrast, application programs such as browsers, word processors, or audio or video players use a separate area of memory, user space. This separation prevents user data and kernel data from interfering with each other and causing instability and slowness,[1] as well as preventing malfunctioning applications from affecting other applications or crashing the entire operating system. Even in systems where the kernel is included in application address spaces, memory protection is used to prevent unauthorized applications from modifying the kernel.