The SID_AND_ATTRIBUTES structure represents a security identifier (SID) and its attributes. SIDs are used to uniquely identify users or groups.
typedef struct _SID_AND_ATTRIBUTES { // saa PSID Sid; DWORD Attributes; } SID_AND_ATTRIBUTES ;
A group is represented by a SID. SIDs have attributes that indicate whether they are currently enabled, disabled, or mandatory, and how they are used. A SID_AND_ATTRIBUTES structure can represent a SID whose attributes change frequently. For example, it is used to represent groups in the TOKEN_GROUPS structure.