The Finder icon is the very first icon on your Dock.  Note that you are unable to move it.  If you do not have any Finder windows open and you click on the Dock icon, you will be taken to your Home folder.

The Finder is a GUI based application that Macintosh users use to navigate and work with the file system, launch applications, and so on.  Finder allows the user to access almost anything on the system such as hard drives, folders, files, CD/DVD drives, and applications.  You're able to view, access, search, and locate just about anything on your Mac within Finder.  You can move things around, copy files and folders, perform searches, and delete things you no longer need. Windows users often perform these tasks with Windows Explorer.

Whenever you click on a Hard Drive, shortcut to a folder, external devices such as a USB device, and so on you open up a Finder window.  There are five ways to view things in Finder:

• by icon
• by list
• by path
• with Finder Coverflow
• Quick Look
  

Note that the latter two were introduced in Mac OS X Leopard.

Mac OS X Leopard introduced a new look to the Finder due to the two new views and also as a result of bringing a more unified look and feel within Mac OS X and applications such as iTunes.  The left side of a Finder window is called the Finder Sidebar.

You can also perform Spotlight searches from within a Finder window and view the results.  Compared to early versions of the operating system, the Spotlight supplement to Finder has brought forth features such as Smart Folders.

Updates

• July 13, 2008 - content revision and modification - added Leopard Finder image
• February 26, 2009 - content revision
• May 27, 2009 - content revision