What is the source order ?

About

The source order is the order of the element in the html document from top to bottom.

Because this is the default visual and keyboard navigation order, correct source order is important for:

• speech,
• sequential navigation (such as keyboard navigation),
• and non-CSS User Agents such as search engines, tactile browsers, etc.

Source order is one of the three order for html elements next to visual and tab order.

Example

In this html document, the heading h1 is before the paragraph p

<h1>Title</h1>
<p>Lorem Ipsum</p>