Memory protection

Memory protection (or protected memory) is a system to prevent one program from corrupting the memory (or other resources) of any other, including the operating system. Memory protection usually relies on a combination of hardware (a memory management unit) and software to allocate memory to processes and.

Description
The effectiveness of memory protection varies from one operating system to another. In most versions of Unix, it is almost impossible to corrupt another process' memory, except in some archaic implementations such as (not to be confused with Linux).

History
In 1993, Windows NT became the first version of Microsoft Windows to offer protected memory. Early Macs running classic Mac OS had no form of memory protection until the introduction of the Mac OS nanokernel in 1994 for PowerPC-based systems. Though protected memory prevents a problematic application from corrupting the memory used by other software, a sandbox goes further by limiting any access at all to protect a user's private information.