Just to be sure:
Integrated amp - preamp and power amp combined in one piece of gear.
Receiver - integrated amp with an AM/FM tuner included.
Preamp - you connect your input devices (cd players, DACs, tape decks, etc.) to it. You select which device you want to listen to, set the volume, it may have a balance control, etc. You then connect it to a power amp.
Power amp - usually has one input where you connect your preamp and a set of speaker terminals to connect speakers. It provides the power to drive your speakers.
Integrated amp - preamp and power amp combined in one piece of gear.
Receiver - integrated amp with an AM/FM tuner included.
Preamp - you connect your input devices (cd players, DACs, tape decks, etc.) to it. You select which device you want to listen to, set the volume, it may have a balance control, etc. You then connect it to a power amp.
Power amp - usually has one input where you connect your preamp and a set of speaker terminals to connect speakers. It provides the power to drive your speakers.