Fixed positioning is a subcategory of absolute positioning. Fixed positioned element doesn't move with scroll it is always fixed with respect to the browser's viewport.
Example of Code
<style type="text/css">
.example-absolute {
position: absolute;
top: 500px;
left: 60px;
height: 2000px;
background-color: limegreen;
}
.example-fixed {
position: fixed;
top: 10px;
left: 10px;
background-color: gold;
width: 90px;
padding: 20px;
}
</style>
<body>
<div class="example-absolute">
This tall div is absolutely positioned 500 pixels from the top and 60 pixels from the left of its containing block.
</div>
<div class="example-fixed">
This div is using a fixed position of 100 pixels from the top and 60 pixels from the left of its containing block. When this page scrolls, this box will remain in a fixed position - it won't scroll with the rest of the page. Go on - SCROLL!
</div>
</body>
Output
This tall div is absolutely positioned 500 pixels from the top and 60 pixels from the left of its containing block. This div is using a fixed position of 100 pixels from the top and 60 pixels from the left of its containing block. When this page scrolls, this box will remain in a fixed position - it won't scroll with the rest of the page. Go on - SCROLL! 