Integrated power amp....
An "integrated power amp" means that the AM/FM receiver and amplifier are in the same physical unit. It's hard to find just a regular "receiver" these days, as 99% of what is sold in the consumer market is, in fact, an integrated amplifier and receiver in one unit.
Your Sansui can be used with another receiver, or another amplifier, or another integrated receiver amplifier! If you use the "Rec Out" jacks on your Sansui to attached another amplifier, then you can add additional speakers in another room, etc. The connection possibilities are quite varied. You will, of course, have to use the volume control on both units to control the speaker volume attached to each independant unit.
Greg