When to use DIV and SPAN - what is the difference ?

What is the difference between HTML tags DIV and SPAN ? When should be each of them used ?

To onefive:

<div>: A block-level element used to group larger sections of a webpage. It starts on a new line and is mainly used for layouts, sections, and containers.

<span>: An inline element used to style or target small parts of text or content without creating a new line.