ألحق حمل وحل جمل على القواعد والكلمات بس حتعجبك أوى

[mostafa ali zaki]

Hello every colleague
when we use mustn't to express prohibition it is the same as can't. is this right or there is a difference in meaning
for example we say
* You mustn't smoke here. It is against the law.
We also say:
* You can't smoke here. It is against the law.
What do you think?