Editing Computer memory (section)

=== Protected memory ===
{{Main|Memory protection}}
Protected memory is a system where each program is given an area of memory to use and is prevented from going outside that range. If the operating system detects that a program has tried to alter memory that does not belong to it, the program is terminated (or otherwise restricted or redirected). This way, only the offending program crashes, and other programs are not affected by the misbehavior (whether accidental or intentional). Use of protected memory greatly enhances both the reliability and security of a computer system.

Without protected memory, it is possible that a bug in one program will alter the memory used by another program. This will cause that other program to run off of corrupted memory with unpredictable results. If the operating system's memory is corrupted, the entire computer system may crash and need to be [[Reboot (computing)|rebooted]]. At times programs intentionally alter the memory used by other programs. This is done by viruses and malware to take over computers. It may also be used benignly by desirable programs which are intended to modify other programs, [[debugger]]s, for example, to insert breakpoints or hooks.