There is a difference of functions between b/strong and i/em?

Question

Do they do something different although they look the same?

Answer 1

Much Difference.
Strong and Emphasized text aslo gives speech to text output if availble. Strong is bold text with priority more than it.
Same for italic.
So its like a heroine and her wax statue.
No difference in looks but strong has got priority, which matters.

Answer 2

There is no difference in terms of browser as they both show that the text is important