So all SMD components are loaded into a rail gun. Try to imagine this, bullets in an ammo belt. However that ammo is merely only millimeters in size.

Here we see rolls and rolls of small SMD components like resistors to be used with the component gun. This you can consider as the machines 'ammo'.

Zoomed in a little, the safety glass makes it hard to photograph though. This is the actual component gun. I'm not joking when I say it is mounting 5 to 10 components per second.