Smash in badminton is the most powerful weapon. you can use smash for building pressure on your opponent and also you can hit a fake smash if you are good in all four types of smashes.
If you think that there is only one way to smash, you MUST watch this video. 4 Types of Smashing technique
1) Full smash (Heavy smash)
2) Half smash
3) Flick smash
4) Slice smash