Tethered. Untethered. No tether. He tether. She tether. With Apple constantly squashing jailbreaks, it is can be confusing to know if your specific iPhone/iPod/iPad can be jailbroken or not. Thus a chart was created (I did not create it) to help people determine which iDevices can be jailbroken. The chart is split up by device and iOS version, making it very easy to see if your iDevice (whether it is an iPhone, iPod Touch, or iPad) running on X version of iOS can be jailbreak’ed or not. Take a look for yourself:
Click on the chart to view it in full size.
The chart is very easy to read. Find your iDevice at the top and scroll down until you find the version of iOS your device is running. Whatever it says in the cell where the row and column meet is your answer. If the cell is red and says “No Jailbreak” that means your iDevice on that version of iOS cannot be jailbroken. If the cell is in green and says “Tethered Jailbreak” that means your iDevice on that version of iOS can be tethered jailbroken. If the cell is in yellow and says “Untethered Jailbreak” that means your iDevice on that version of iOS can be untethered jailbroken.
If you happen to own an iDevice that can be jailbroken, feel free to read dotTech’s guide on how to jailbreak . An older guide  explains the difference between tethered and untethered jailbreaks.
Welcome to the free world. Don’t kid yourself — it is a jungle out here.