Differences between <I> and <em>, <B>, and <strong> labels-Separation

& Lt; I & gt; and & lt; em & gt;, & lt; B & gt; and & lt; strong & gt; the difference between labels-falls in HTML4.01:
<B> <I> Yes Visual elements(Presentationl elements), indicating meaningless bold, meaningless italic, It only indicates that the style is in bold or italic.The two labels are not recommended in HTML4.01. We recommend that you use CSS styles;

<Em> and <strong> YesExpression Elements(Phrase elements ). <Em> (emphasized text) indicates general emphasis texts, while <strong> (strong emphasized text) indicates more emphasis texts than <em>. These two labels have semantics.The content in this tag is more important in search engines, and some voice readers will also strengthen their tone when reading it.

That is to say, if you want to show some text in bold or italic, you should use labels and define CSS styles for it. If you want to emphasize a part of text in semantics, for example, the keyword should be usedAndTag,Label representation RatioMore emphasis on labels.