Read out more about string vibrations and standing waves.
Next you would dwell more upon the fundamental frequencies of vibration and the higher harmonics.
Next you would understand about how by fretting the string your are actually creating a node, and thus a standing wave. And that a note is not really a pure frequency but a combo of fundamental + harmonics.
Now when a note = fundamental + harmonics; then only certain combos of notes will sound good because the harmonics will ensure that the strings do no vibrate in "harmony" unless the fundamentals and harmonics follow certain mathematical rules (ratios).
This is the reason behind intervals.
Stacking up of 2 or more intervals = chord.
Now you have the laptop. Read more about this stuff on wiki/google/bing/yahoo etc
You donít get what you deserve, you get what you negotiate.