Apparently the resolving phase takes all of the actions that both players did on their turn and places them on a single resolving stack. Remember, all actions you did on your turn never actually happened until they resolved.
Instead of using LIFO (Last in First out), Infinity Wars uses "Initiative" to support the design of both players taking their turn at the same time. This is genius imo.
When you understand how the stack resolves, everything clicks.
Resolving the stack is as follows...
1. Any characters moved to different zones or any characters casted and brought into play are done so right away. Initiative does not affect this portion of the stack.
2. Any spells or character abilities are resolved in this portion. First the spells and character abilities of the player with initiative, then the spells and character abilities of the other player. Anything killed in this phase will not participate in the attack resolving portion.
3. All characters in the attack zone of the initiative player attack first. Attackers are designated left to right. Defenders also defend left to right. Each character attacks once unless the character is unstoppable or has an ability like FD Coyle.
4. All characters in the attack zone of the other player attack next following the same rules.
5. When all of these phases are done, final checks are made such as health and morale values. Initiative does not decide which values are checked first. This is why draws can more likely happen. In MTG you can get a draw if both players kill each other while a stack is resolving, although in infinity wars....both turns are merged into one giant resolving stack.
Hopefully that clears things up for someone that is familiar with MTG rules (or confuses the heck out of ya xD).