Very good question. Read this, as an amplifier has many internal parts.
http://electronics.howstuffworks.com/amplifier2.htm
In laymans terms, your 7 channel receiver has 7 channels which pull power from a single power supply, utilizing two capacitors which store energy (similar to a battery but with recharging capabilities), and dissipate the heat byproduct from the transistors with a single heat sink. In comparison, your receiver is not comparable to 7 monobloc 110 watt amplifiers with individual power supplies, capacitors, and heat sinks.