Difference between i tag and em tag

<i>

• It is one of the element of HTML which is used in formatting HTML texts. It is used to define a text in technical term, alternative mood or voice, a thought, etc.

<em>

• It is also one of the element of HTML used in formatting texts. It is used to define emphasized text or statements.

By default, the visual result is the same. The main difference between these two tag is that the <em> tag semantically emphasizes on the important word or section of words while <i> tag is just offset text conventionally styled in italic to show alternative mood or voice.