The use of atomic weapons at the end of World War 2 fostered fears about their potential use during the Cold War years.
Interrupts and signals are low-level mechanisms that can alter the flow of control in a way similar to a subroutine, but usually occur as a response to some external stimulus or event (that can occur asynchronously), rather than execution of an 'in-line' control flow statement.
Transaction Control (TCL) statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions. 1  COMMIT - save work done.  SAVEPOINT - identify a point in a transaction to which you can later roll back.