Energy Resources:

Natural resources we can use to produce energy (oil, coal, natural gas, nuclear, biomass, hydro, wind, solar, geothermal, ocean).

Energy Conversion:

The steps that turn a raw energy resource into an accessible source of energy for human use (steps include exploration/siting, mining/production, refining/conversion, and distribution).

Energy Carriers:

Allows for the easy transportation of energy to an end-use (electricity, hydrogen, gasoline)

Energy Services:

End-use of energy (heating, cooking, illumination, refrigeration, cooling, manufacturing, agriculture, water pumping, defense, mobility, )

Economic Impacts:

Standard of living/affluence, resource depletion, trade balances, costs of energy (direct, and indirect--health care costs, etc).

Environmental Impacts:

Air and water quality, waste, radioactivity, thermal pollution, noise pollution, electromagnetic effects, climate change, biodiversity effects.

In the U.S., 41% of primary energy use was to produce electricity, mostly for buildings. Of that, 65% was lost in conversion, and 35% was put to use. This 35% is equivalent to 3.9 trillion kWh (3900 TWh) of usable electricity.¹

References:
(1) EIA Annual Energy Review 2006, p. 221