Oddly enough, I expected that running with that cadence would fatigue me much faster, but midway through my first run, I found myself being less fatigued than my previous technique.
Also, try to keep your head in the same virtual horizontal line. Head/torso going up and down can cost up to 40% more energy.
For extra points, your torso shouldn't be swaying, arms moving should be enough.
YouTube marathon runners for Olympics and look at some training videos for in depth info.
Just had to point out this delicious tautology.
Anyway, I don't think you can sum up correct running form in words, or if you can then it's not useful. My advice would be: keep your tempo (steps/minute) around 170-180, do ankle mobility work and hip/glute strengthening. A high tempo lessens time in air each stride and thus velocity when hitting the ground, lowering impact on joints. Ankle/hip/glute work will stave off most muscular imbalances, which are the root cause of many form problems.
Just had to point out this tasty contradiction. ;)
They process is entirely different.
It's imprecise language, to be sure. I think it's more about where you're concentrating the force. If you look at the .gif that 'WalterSear shared down-thread, you'll see that the greatest force is just before the heel lifts, not after.
That's the difference, I think, between "pushing off" with the heel or the forefoot: where, specifically, in the stride the maximum force is applied.