A queue is a special kind of linked list where each new element is inserted to the head and removed from the tail of the linked list. I do not need a figure to describe a queue; imagine going to a bank and waiting for the people that came before you to finish their transactions before you can talk to a bank teller.
The main advantage of queues is simplicity. You only need two functions to access a queue, which means that you have to worry about fewer things going wrong and you can implement a queue any way you want as long as you can offer support for those two functions.