Explain the Fork-join

This is primitives in a higher level programming language for implementing interacting processes. The syntax is like this:

fork ;
join ;

where is a label related with some program statement, and is a variable. A statement fork label1 reasons for creation of a new process that begins executing at the statement with the label label1. This process is concurrent along with the process that executed the statement fork label1.A join statement synchronizes the birth of a process along with the termination of one or more processes. Fork-Join offers a functionally entire facility for control synchronization.