<Div>: Div is block level element. It defines a block of text. It creates a line break before and after, forcing the browser to render the text following on the next line down.
<Span>: span is inline level element. It doesn't cause a line break. It delimits text. It allows styles to be applied to an 'elemental' region, or for the 'elemental' region to be identified, without causing a break in the text flow.