 Another data type structure that we can work off of is something that we classify as a Q. And a Q is pretty much the exact opposite of a stack. The best example, since we've all probably been there, is I'm at... That's a terrible rendition of a checkout counter. And here's our little store clerk making minimum wage. Should get a computer science degree so he doesn't have to do this. Now, as a Q operates, let's say for example someone in a terribly drawn shopping cart rolled in. There we are. So what's going to happen is this person just happened to become person number one. If there's no one else in the checkout line, then person one goes immediately to the checkout counter. But what happens if another poorly drawn shopping cart came in with another poorly drawn person buying whatever is that they wanted to buy today? Well, since shopping cart number one, this person is still being processed by the checkout counter, this person has to wait. And eventually when, say for example, what we would classify as our... Sorry, not pop, we don't use pop since that's a stacked term. We would classify as a DQ. As soon as this first shopping cart DQs, then shopping cart two can move forward and get processed. But that same operation as we continue to imagine as more and more poorly drawn shopping cart people show up, they're getting their own operation of, sorry, NQ in which I'm coming in and I'm now in this case, if we still are, if our person one is still going through the process, this person would be number two on the list and this person would be number three on the list.