What is difference between Flash and Unlock Code and how to use Flash Code and Unlock Code

I have given many modem unlocking solution for various modems and mobile phones e.g. Huawei, ZTE, Alcatel, Micromax, Airtel, Vodafone, Teracom, Aircel, Idea, Reliance, Tata Docomo, BSNL, Nokia, Samsung, Siemens, Maxon, NEC, Sony, Panasonic, Vitel, AEG / Telital, Alcatel cellphones. We have mentioned in some article about flash code and in some article about unlock code. Many of users are confused between flash code and unlock code.

Here, we will describe you in detail about flash code and unlock code. When you download any firmware from the internet and upload it to your modem (Huawei, ZTE, Alcatel, Teracom, Micromax) then it asks you the password.
As you can see in the above screenshot, when you will update / downgrade the firmware of your modem then it asks you for password. Here, you have to use flash code which you have generated using any unlock code tool. When you will provide here flash code then only you can proceed to the next screen. Here, your modem will be flashed and it opens the door for unlocking.

Now coming to the unlock code. Some modem only unlocked with the unlock code but some modem needs to flashing it. After the flashing modem when you insert another than default sim in your modem (another network provider sim) then it asks for the password / unlock code. 
In this case you have to use the unlock code which you have generated using any unlock code generator tool.
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