The task state segment (TSS) is a structure on x86-based computers which holds information about a task. It is used by the operating system kernel for task management. Specifically, the following information is stored in the TSS:
Processor register stateI/O port permissionsInner-level stack pointersPrevious TSS link
All this information should be stored at specific locations within the TSS as specified in the IA-32 manuals.