What field contains a record's 32-character, unique identifier?

`sn_rec_id` is not a standard ServiceNow field name for a record's unique identifier.

`rec_id` is not a standard ServiceNow field name for a record's unique identifier; the correct field is `sys_id`.

`u_id` is not a standard ServiceNow field name for a record's unique identifier; fields starting with `u_` are typically custom fields.

The `sys_id` is a 32-character hexadecimal string that serves as the unique identifier for every record in every table within a ServiceNow instance, ensuring global uniqueness and referential integrity.

`sn_gu_id` is not a standard ServiceNow field name for a record's unique identifier.

`sn_sys_id` is not a standard ServiceNow field name for a record's unique identifier; the correct field is simply `sys_id`.

`id` is too generic and not the specific field name used by ServiceNow for a unique record identifier; it's often used in other systems but not as `sys_id` in ServiceNow.