Categories: containers, adaptors
Component type: type
A queue is an adaptor that provides a restricted subset of Container functionality A queue is a "first in first out" (FIFO) data structure.  That is, elements are added to the back of the queue and may be removed from the front; Q.front() is the element that was added to the queue least recently. Queue does not allow iteration through its elements. 
Queue is a container adaptor, meaning that it is implemented on top of some underlying container type. By default that underlying type is deque, but a different type may be selected explicitly.