Pending signals are those signals that have been sent to a process but not yet have been delivered. This happens when a signal mask blocks a particular signal for e.g. in the previous questions we have masked SIGTERM i.e. it is pending. The concept of pending signals ensure that no signals are lost, they are simply delayed until the process is ready to handle them. Other scenario where they can be marked as pending are when multiple signals are sent to the process, they are marked as pending.
