2. Why Icon? An icon is a small picture that represents a file. Icons help you execute commands, open programs or documents quickly. It is also useful to recognize quickly an object in a browser list. For example, all documents using the same extension have the same icon

3. Related question What's the difference between a standard image and an icon image? What's the structure of an icon? How to create an icon which will display correctly on all screen configurations (size, colors...)? Can we save an icon to a file? Can we assemble several icons into one file?

4. What are the differences between an image and an icon? Icons are different from standard images A computer image is a bitmap or vector picture, which can be saved using various formats (BMP, PSD, GIF, JPEG, WMF...). They are have standard sizes (usually small): 16x16, 32x32, 48x48... One icon is composed of several images The most important property of an icon is the ability to include transparent areas

5. What is the structure of an icon? An icon is a group of images of various formats (size and colors) You need to include several images in an icon to permit Windows® or Macintosh® OS to choose the appropriate format when displaying it on screen

6. Can we save an icon to a file? Yes, the extension for a Windows® icon file is "ICO". The extensions for Macintosh® icons are "ICNS", "RSC", "RSRC" and "BIN". Can we save several icons into one file? Yes, you can assemble several icons in one file called an Icon Library. The extension for a standard Icon Library is ICL.