ULK --- Chap3 Processes: Relationships Among Processes

Processes created by a  program have a parent/child relationship. When a process creates multiple children,

these children have sibling relationships. Several fields must be introduced in a process descriptor to represent

these relationships; Processes 0 and 1 are created by the kernel; as we will see later in the chapter, process 1

(init) is the ancestor of all other processes.