As mentioned above, when an element is floated, it is taken out of the normal flow of the document (though still remaining part of it). It is shifted to the left, or right, until it touches the edge of its containing box, or another floated element.
In this example, there are three colored squares. Two are floated left, and one is floated right. Note that the second "left" square is placed to the right of the first. Additional squares would continue to stack to the right, until they filled the containing box, after which they would wrap to the next line.
A floated element is at least as tall as its tallest nested floated children. We gave the parent width: 100%
and floated it to ensure it is tall enough to encompass its floated children, and to make sure it takes up the width of the parent so we don't have to clear its adjacent sibling.
HTML
<section>
<div class="left">1</div>
<div class="left">2</div>
<div class="right">3</div>
<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Morbi tristique sapien ac erat tincidunt, sit amet dignissim
lectus vulputate. Donec id iaculis velit. Aliquam vel
malesuada erat. Praesent non magna ac massa aliquet tincidunt
vel in massa. Phasellus feugiat est vel leo finibus congue.</p>
</section>
CSS
section {
box-sizing: border-box;
border: 1px solid blue;
width: 100%;
float: left;
}
div {
margin: 5px;
width: 50px;
height: 150px;
}
.left {
float: left;
background: pink;
}
.right {
float: right;
background: cyan;
}
Result