Definition:
An alias is a small file that serves as a link to another object in the Mac file system. An alias is dynamic; if you move the original object, perhaps to a different folder, the alias will still know where it is. You can immediately recognize an alias by its icon, which has a small black arrow in its lower left corner.
An alias is a quick and easy way to access a file that may be buried several folders deep.
Examples:
A Finder window's sidebar contains a list of files and folders. All of the items in the list are aliases to the original objects.
