A footprint is a physical layout that defines where an electronic component connects to a circuit board. Footprint pads are the copper contact areas within a footprint where component leads are soldered.
The commands for placing surface-mounted device (SMD) and plated through-hole (PTH) pads are uniquely used in the Footprint Editor. Because footprints are spatially accurate on the circuit board, it is important to precisely manage pad size, shape, and placement.
SMD pads are most commonly used because of their compact size. PTH pads provide a more robust construction, but are physically larger than SMD pads.
Move and Group commands are useful for creating a line of evenly spaced pads for one side of a component, then copying it for the pads on the other side of the component.