Device/Devices template monitors interfaces

Hi

I need help to understand this. I created a device class under Devices and add a Cisco device under the new device class. When I look at template selected for the device class it is only Device (/Devices). When I look at Data Source for Device (/Devices), there is only sysUpTime. However when I check the Cisco device, it has a lot of graphs for interfaces under "component". How is the Device(/Devices) link to this "component" interfaces graph. I see that the template for this interfaces graphs is ethernetCsmsCd_64/*Devices but I cannot figure out how is it linked to template Device(/Devices).

I am asking this as I am thinking if just adding a device to Device(/Devices) I can get all these interfaces graphs, should it not show ....my Linux CPU or memory too if I add Linux server to Device (/Devices)

Thanks