Two questions - Bombardment and Defence

[jthompson333]

What does defense mean when it comes to hero bonuses?

Is there a different button for "Planetary Bombardment" than "Bombing Run?"

[Mat8876]

1. A defence bonus is an effect that causes all units on a battlefield to be able to live longer while under attack.

2. Bombing run's button is the top button (out of four) to the right of the mini map, Planetary bombardment is to the left side of any units selected.