Icon, that's the people name it. This icon is an image with relatively small size which “. png “and “.ico” extension. With the icon you can decorate a blog, so look more beautiful. But how you can get this icon? Do not be confused because there are many on the internet site that provides the icon for free, you only download it and install at your blog.
One sites provide the icon that I like this is http://www.iconarchive.com/ , because on this site there are many different icon with categories.
If you need icons try visit the site. Find the icon that matches your needs.