The glossary below contains many of the terms you will find in common use throughout the Symantec Security Response website. Please refer to this list to find definitions of terms and answers to other Internet security-related questions.


An operating system that contains the code that is used to perform tasks on a client computer that cannot be performed while the client computer's operating system is running. Also used when the client computer has no operating system installed (a "bare metal" computer), for example, when restoring images.