Understanding single sideband modulation and demodulation
In the first diagram (broadcast AM) "the message" is a sinewave of frequency \$\omega_m\$. In the second diagram (full AM suppressed carrier modulation) "the message" is also a sinewave of frequency \$\omega_n\$. OK so far? - "the message" signal or modulating signal is just a plain ordinary sinewave.

Either of these two methods produce two sidebands at either side of the carrier frequency. So if the carrier were 1 MHz and the modulation ("the message") were 2 kHz, you would see frequencies of 998 kHz and 1002 kHz on a spectrum analyser. These are the upper and lower sidebands.

If you filtered out the upper sideband you would be left with only the lower sideband and if this was mixed (in a receiver) with a sinewave of 1MHz, you'd recover the original modulating frequency (aka "the message").


  Please explain in TIME domain with diagram. Please focus on conceptual
  treatment rather than individual techniques of modulation and
  demodulation.


No I'm not going to do that. If you don't understand my words then please let me know.