Definitions for "Security identifier"
A structure of variable length that uniquely identifies a user or group on all Windows NT implementations. See also access token, impersonation token, primary token, privilege.
(SID) A data structure of variable length that identifies user, group, and computer accounts. Every account on a network is issued a unique SID when the account is first created. Internal processes in Windows refer to an account's SID rather than the account's user or group name.
a number that uniquely identifies a computer in a network
Keywords:  sender
Keywords:  see
See security ID.