The physically rotating wheel was surrounded by another wheel of buttons. the Click Wheel didn't appear until the mini. 1st gen: mechanical wheel with a surrounding wheel of buttons. 2nd gen: touch wheel surrounded by buttons. 3rd gen: all touch with a row of buttons under the screen.
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The first iPod had the wheel, but it physically rotated. It did have the piezo clicker too though.
The physically rotating wheel was surrounded by another wheel of buttons. the Click Wheel didn't appear until the mini. 1st gen: mechanical wheel with a surrounding wheel of buttons. 2nd gen: touch wheel surrounded by buttons. 3rd gen: all touch with a row of buttons under the screen.
http://support.apple.com/kb/HT1353 identifies the iPod (Click Wheel) as their 2004 model.