Opacity means a certain degree that is applicable to light that passes through the objects in the pages. Actually, in CSS3 we control the transparency of any HTML elements by using opacity. It makes the images clear and visible. We can control opacity in two ways.
First: We can declare it by @media or @import at-rules of specific target medium:
@import url("fancyfonts.css") screen;
@media print {
/*style sheet for print goes here*/
}
Second: Within the HTML4 document, we can declare the media attribute.
<!DOCTYPE HTML PUBLIC"-//W3C//DTD HTML 4.01//EN">
</HTML?
<HEAD>
<TITLE>Link to a target medium</TITLE>
<LINK REL="stylesheet" TYPE="text/css"
MEDIA="print,handheld" HREF="foo.css">
</HEAD>
<BODY>
<P>The body...
</BODY>
</HTML>
