<div>   </div>

The div tag is used to group various other HTML elements. It is a block level element. We can say it also create a block.

Ex:-

<div> This is a Div Tag </div>

<div>
	<h1> Heading </h1>
	<p> Para </p>
</div>

<span>   </span>

The span tag is used to group inline elements. It is an inline element.

Ex:-

<p> I am example of span tag </p>

<p> I am <span>example of span tag</span> </p>