A “receiver” is an integrated amp (so pre-amp plus power-amp, which you seem to be thinking of as “speakers amp”, all in the one box) that includes a radio tuner (i.e. it receives radio signals). Not sure there’s much use for them any more, given you can get radio channels in apps/programs on a mobile, tablet, PC etc and feed them in via a DAC. Thinking of which, some active/powered speakers include the DAC stage too, while some don’t…