www.what-is-exe.com
This is a link to a great site defining all those annoying file names you sometimes see on Windows. You can look up the definition of .dll or .exe and many others.
Oh Yeah!!! I started this here blog with the question: where are the mirrors in the Universe? And here it is: http://apod.nasa.gov/apod/ap080625.htm. Wow. I had a feeling this idea was correct because even in ponds we see "mirrors". Your eyes are mirrors. In a sense the mind is a kind of mirror.