This circuit shows how an Pnp-Npn set of transistor is turned on.The base of the Npn get "Pulled UP" and when it happens, the base of Pnp gets "Pulled Down" over the Npn.With this configuration we can connect our load to ground.(ground returned load).
And we can discard base-collector 180 phase difference.Because we connect our load to pnp collector.
