Favicons have come a long way since they were first introduced in Internet Explorer. The favicon was created by Microsoft for Internet Explorer but at that time it did not conform to the W3C HTML recommendation because the rel
attribute has to contain a space-delimited list of link types, the .ico didnt have a registered MIME type and using a reserved location is what is know as link squatting or URI squatting to the W3C.
When someone looks through their bookmark links or at the address bar and sees your logo or image as the favicon on your site, it shows that you care to go the extra mile when it comes to design and branding.
Before, these 16 by 16 pixel images placed in the root of a server, were called favicon.ico and were only used for bookmarks. This brought about a security concern among website visitors since webmasters could see the amount of people that had bookmarked the site by taking a peek at the access logs and see how many downloaded the favicon.ico file. Now browsers just display the favicon in the address bar on every visit making it less of a security issue. The image formats have expanded as well to included animated gifs and PNG’s. Although putting the favicon at the root of a server is still sometimes practiced, it is generally perfered that you use a piece of html in the <head> section that points to the location of the favicon. It looks like this:
<link rel="shortcut icon" href="http://yoursite.com/favicon.ico" mce_href="http://yoursite.com/favicon.ico" type="image/vnd.microsoft.icon">
<link rel="icon" href="http://yoursite.com/favicon.ico" mce_href="http://yoursite.com/favicon.ico" type="image/vnd.microsoft.icon">
<link rel="icon"
type="image/png"
href="/somewhere/myicon.png" />;
Or if your document is XHTML, you use this:
Now although it is not 100% guaranteed that the favicon will always display on every browser every time, I believe it to be a good practise to integrate on into your website. When someone looks through their bookmark links or at the address bar and sees your logo or image as the Favicon on your site, it shows that you care to go the extra mile when it comes to design and branding. In website design, image is everything so why not put your image everywhere!