Queue is a liner list of element in which deletion can take place only at on end, called front and insertion can take place only at one end, called rear. It uses first in first out (FIFO) policy. A queue can be considered as a sequence of item.
A queue has following essential property.
A- A container of items , that contains queue elements.
B- A pointer front, that point the first element of the queue.
C- A pointer rear ,that point the last element of the queue.
1- There is an add operation. It means to add a item in the queue. Addition is only at the rear end of the queue.
2- There is an deletion operation it means to remove an item from the queue. deletion is only at the front end of the queue.
3- Only the end items (front –rear) are visible and accessible .