Question

capacitor and inductor store energy. why not resistor?

Answer 1

The inductor stores the energy in electromagnetic form. The resistor while dissipate it in heat form, Resistor does not store energy. ... Charges through inductor produces magnetic field and in capacitor produces electric field.

Answer 2

A capacitor stores electrons as static charge, an inductor as a magnetic field. 
A resistor is a plain passive device.

If you think of electricity as water, a capacitor is like a rubber membrane across a pipe, an inductor is like an axial turbine (water makes it spin, it continues to spin and pump water a while after the flow has stopped), resistor is just like a pipe whose dimensions determine the rate of water flow.