Sentence:  <WSD>Queue</WSD> implementations are commonly based on insertion order as in first-in, first-out (FIFO) queues or last-in, first-out queues (LIFO queues are also known as stacks). 
Meaning of the word marked with <WSD> tags:  A data structure in which objects are added to one end, called the tail, and removed from the other, called the head (- a FIFO queue). The term can also refer to a LIFO "queue" or stack where these ends coincide. (from 20th c.)