To find out which iPod touch model you have, note the amount of storage capacity your model has, if it has a color screen, dock connector, clip and camera. You can then use that information to find out what model you have. (To find out the storage capacity: choose “General” or “Settings” and “About”).
- The 5th generation iPod Touch (2010-2012) has a Multi-Touch display and has 32 GB or 64 GB of storage available.
- The 4th generation iPod Touch (2010-2011 or 2009 – 2010) has a Multi-Touch display and 8 GB, 32 GB or 64 GB of storage available. It is available in black and white and has two built in cameras.
- The 3rd generation iPod Touch that came out in 2009 has a Multi-Touch display and 32 GB or 64 GB of storage available. It also has a 3.5 inch widescreen and the capability to browse Safari and watch YouTube videos with Wi-Fi. It also allows you to search, preview and buy iTunes music.
- The 3rd generation iPod Touch that came out in 2008 has a Multi-Touch display and 8 GB, 16 GB, or 32 GB storage available. To tell this version apart from a 2nd generation iPod Touch, look at the model numbers on the back of your iPod. If you see the model number A1288, it’s a 2nd generation model, and if you see the number A1318, it’s a 3rd generation model.
Source: Apple Support