What's the difference between and , and ?

Answer 1

and add extra semantic meaning to your document. It just so happens that they also give a bold and italic style to your text.

You could of course override their styling with CSS.

and on the other hand only apply font styling and should no longer be used. (Because you're supposed to format with CSS, and if the text was actually important then you would probably make it "strong" or "emphasised" anyway!)

Hope that makes sense.