stacks and queues in this different kind of structure stacks queues in this we'll examine three data storage structuresthe stackthe queueand the priority queue we'll begin by discussing how these structures differ from arraysthen we'll examine each one in turn in the last sectionwe'll look at an operation in which the stack plays significant roleparsing arithmetic expressions different kind of structure there are significant differences between the data structures and algorithms we've seen in previous and those we'll look at now we'll discuss three of these differences before we examine the new structures in detail programmer' tools arrays--the data storage structure we've been examining thus far--as well as many other structures we'll encounter later in this book (linked liststreesand so onare appropriate for the kind of data you might find in database application they're typically used for personnel recordsinventoriesfinancial dataand so on--data that corresponds to real-world objects or activities these structures facilitate access to datathey make it easy to insertdeleteand search for particular items the structures and algorithms we'll examine in this on the other handare more often used as programmer' tools they're primarily conceptual aids rather than full-fledged data storage devices their lifetime is typically shorter than that of the database-type structures they are created and used to carry out particular task during the operation of programwhen the task is completedthey're discarded priority queues parsing arithmetic expressions