What is the difference between a stack and a queue?

Queue	Stack
First item to be inserted is the first one to be removed.	Allows access to only last item inserted.
This mechanism is called First In First Out (FIFO).	An item is inserted or removed from one end called the “top” of the stack. This is called Last In First Out (LIFO) mechanism.
Placing an item in the queue is called “enqueue or insertion” and removing an item from a queue is called “dequeue or deletion”. Pre J2SE 5.0, you should write your own Queue class with enqueue() and dequeue() methods using an ArrayList or a LinkedList class. J2SE 5.0 has a java.util.Queue interface.	Placing the data at the top is called “pushing” and removing an item from the top is called “popping”. If you want to reverse “XYZ” -> ZYX, then you can use a java.util.Stack