What is a Favicon?

A favicon (short for "favorites icon" and also known as a page icon), is an icon associated with a particular website or webpage that is displayed in the browser address bar next to a site's URL.
You can easily create your own custom favicons for free with Favicon Generator.
How to make a Favicon
Step 1. Locate the image that you would like to use as your Favicon and make sure that the dimensions are perfectly square (ie. 100 Pixels x 100 Pixels).
Step 2. Browse to the file's location on your computer and select the image.
Step 3. Press the Generate Favicon! button below.
Step 4. Right Click Your Favicon above. After downloading, simply rename and upload favicon.ico to your root directory.
Step 5. Copy and paste the code below to the <head> section of your webpages: <link rel="icon" href="/favicon.ico">
The code above will work for all modern browsers, including Internet Explorer 11. For compatibility with older versions of Internet Explorer, you may use the phrase "shortcut icon" instead of just "icon": <link rel="shortcut icon" href="/favicon.ico">
If you want a retina favicon that will work with Apple touch devices, there is just a little additional work to be done. Similarly, for Windows 8 or Windows 10 "metro UI" tile favicons, you will need to conform to certain resolutions and add a background color for the Windows tile. Head over to the Favicon FAQ to learn how to get Windows and Apple favicons to show correctly, and how to make favicons for iPhone, iPad, Android, and Windows devices.
That's all there is to it, enjoy your favicon!