TOpic 7 FIFO World
English National Curriculum:
Key Stage 2
Tooltip content
To use sequence, selection, and repetition in programs; work with variables and various forms of input and output 
learning objectives
Tooltip content
To understand what First In First Out means. 
success criteria
  • I can explain what the concept First In First Out is in programming.  
  • I can add and delete elements from a First In First Out list. 
top tips
  • In queues, we maintain two pointers to access the list, the front pointer and the rear pointer.
  • First In First Out is used here to represent the computer science concept of queues.
  • Queues are sequential data structures that follow the First In First Out principle.
Common misconceptions




Front and Rear

The deletion of an element in a queue is called dequeue operation.

The queue follows the FIFO (First in First Out) principle so the element first inserted in a queue is the first deleted.  

The insertion of an element in a queue is called enqueue operation.  

In a queue, we have two pointers to indicate the rear and the front of the queue.

FIFO is Short for First In, First Out, It is a method of processing data where the data first received is the first to be sent out after processed. With FIFO, the data is sent out in the same order it was received.

FIFO is often referred to as a queue in computer science. The operation of adding an element to the rear of the queue is known as enqueue, while the operation of removing an element from the front is known as dequeue.

The operations of a queue make it a first-in-first-out (FIFO) data structure. In a FIFO data structure, the first element added to the queue will be the first one to be removed. This is equivalent to the requirement that once a new element is added, all elements can be removed. A queue is an example of a linear data structure, or more abstractly a sequential collection.

Queues are common in computer programs, where they are implemented as data structures coupled with access routines, as an abstract data structure or in object-oriented languages as classes. Common implementations are circular buffers and linked lists.