Aliases: Greatest Thing since Sliced Bread
An alias is a tiny file that automatically opens the file, folder, disk, or network volume that it represents. Although an alias is technically an icon, it’s different from other icons; it actually does nothing but open another icon automatically when you double-click. Put another way, aliases are organizational tools that let you have an icon appear in more than one place without having to create multiple copies of the file that icon represents.
An alias is very different from a duplicated file. For example, the iTunes application uses around 215 megabytes (MB) of hard-drive space. If I were to duplicate iTunes, I’d have two files on my hard disk, each requiring around 215MB of disk space.
An alias of iTunes, on the other hand, looks just like the original iTunes icon and opens iTunes when you double-click it but requires less than 1MB of hard disk space. So try placing aliases of programs and files you use most often in convenient places such as the Desktop or a folder in your Home folder.
Why else do I think that aliases are so great? ...