Suppose you want to buy a ticket to a concert of your favorite band and you know that the tickets are running out. You need to open your computer, wait for the launch of the browser, go to the website of ticket sales, see there is only one ticket remaining, and click to buy. Then boom, “Sold out” is the phrase you are going to hate for a while. We are sad to say but you are “cold started”. You would have been able to catch the last ticket if your browser window was open, showing the website, and ready for you to click the “buy” button. You should have kept your computer warm to buy this ticket.