Yugioh- what is the difference between main phase 1 and main phase 2?

their really isn't a big difference between them except for the fact in Main Phase 2 you can't attack again if you are planning on setting Spell [S]/ Trap [T] cards face-up or face-down.

what i mean is

- Draw Phase

- Main Phase 1

- Battle Phase

- Main Phase 2

- End Phase

during Main Phase 1 you can set your s/t cards and launch you attack in your battle phase. Main Phase 2 if you can set more s/t cards after your done setting the amount you want to set you'll probably have to end your turn.