This is very easy but the most tricky area where many people are stuck, DFU is the device firmware update mode in which we update the firmware of our device.
When you are trying to jailbreak your device you have to put your iphone, ipod or ipad in DFU mode and steps are given with seconds couting on screen which makes us a little nervous.
I am going to tell you a simpler way so that you can put your device in DFU mode before running RedSn0w and you will receive confirmation message that your device is in DFU mode. Following are steps to put your iphone, ipod or ipad device in DFU mode.
Step 1: Connect your ipod, iphone or ipad to your computer and run iTunes.
Step 2: Press and hold both Power and Home buttons together for 10 seconds. After 10 seconds release the power button but keep pressing the Home button. You will see a pop up message in iTunes as under and release the home button also immediately.
Now your device is in DFU mode and you can start RedSn0w and follow jailbreaking and only need to press next once asked for DFU mode so you will reach to step 8 where you need to select “Install Cydia”.