Normal Flow, or Flow Layout is the way that Block and Inline elements are displayed on a page before any changes are made to their layout. Inline elements display in the inline direction, that is in the direction that words are displayed in a sentence according to the Writing Mode of the document. Block elements display one after the other, as paragraphs do in the Writing Mode of that document. In English therefore, inline elements display one after the other starting on the left, and block elements start at the top and move down the page.
The following example demonstrates Block and Inline Level boxes. The two paragraph elements with a green border are Block Level, and display one under the other.
The first sentence also includes a span element with a blue background. This is inline level and therefore displays in place in the sentence.