Easy-PC uses three sets of libraries, for the graphical representation in the schematic (schematic symbols), for the representation in the PCB (PCB symbols) and across both to tie them together (components).

A component is used by both the schematic editor and the PCB layout editor to tie the two applications together. Typically, a component would be either a generic designation or the part name, such as 74LS00. This would use four NAND2 (2 input) logic gates in the schematic and a DIP14 for the discrete footprint in the PCB, with both of these referenced in the component.

You can create schematic-only Components, these will just have a schematic symbol and component definition, with no PCB footprint. You might use these for power and ground symbols for example.  The component editor allows specific nets to be pre-loaded onto pins where they're being used to label nets, but these are not hard coded onto the pin.  They're the equivalent of using 'Add to Net' on the pin.

Likewise, you can create a PCB-only component which would have just the PCB footprint and component definition, with no schematic symbol. You might use these for testpoints for example, or perhaps for defined mounting holes or fiducial markers..