HTML Block-level Elements:
A block-level element always starts on a new line in html.
A block-level element always takes up the full width available (stretches out to the left and right as far as it can).
A block level element has a top and a bottom margin, whereas an inline element does not.The <div> element is a block-level element.
Example
<div>Hello World</div>
Here are the block-level elements in HTML:
<address><article><aside><blockquote><canvas><dd><div><dl><dt><fieldset><figcaption><figure><footer><form><h1>-<h6><header><hr><li><main><nav><noscript><ol><p><pre><section><table><tfoot><ul><video>
Inline Elements:
An inline element does not start on a new line.
An inline element only takes up as much width as necessary.
This is a <span> element inside a paragraph.
Example:
<span>Hello World</span>