ATMs are responsible of dispensing billions of dollars every month around the world. These ATMs are very accurate and accurately dispense cash. Modern ATMs can also take deposits and can automatically refill them using the deposited cash. Since these machines have thousands of dollars inside them every instant, they are prone to thieves and hackers. So how does the ATM work and how it guards itself from thieves and hackers? This animation explains the functionality of these machines in detail.