A process is represented by a data structure (i.e., a struct or class)- the process control block (PCB).

A thread in a process is also represented by another data structure (i.e., a struct or class) - thread control block (TCB).

A process will have have one or more threads. The PCB may have a pointer to a list of thread control blocks.

The context of a thread is represented by its

• stack
• register state
• process memory
• open files
• ...

The TCB will need to provide access to all components of the thread context.