What is a "favicon"?

Favicon means "favourite icon" and the first thing I learn is that it is that cool tiny graphic on the browser window tab (in Firefox anyways)...  I always wondered how those got there so today I am trying to make myself a favicon for this website. My first attempt was a failure and the text was not readable...   ok so now i've googled "how to make a favicon" and at least now I know that a favicon is a 16 x 16 pixel little icon, so that's a good start for me : )  BUT I need to start with a 64 x 64 pixel graphic in photoshop and design my icon. If I was feeling ambitious I would download a plug-in that would allow me to export the graphic as an ".ico" file...  hmm but for now I'm going to start an easier way by simply making a .png graphic in photoshop-- and voila!  Ok maybe I'll try to make the .ico graphic another day but for now you can see my favicon now (with the letters A S : ) 

Favicon graphic

Favicon graphic