When you create or register a new account on Microsoft azure (https://azure.microsoft.com/en-in/free/), you will get $200 credit (Around 13,300 INR) for use to be Within 30 days of period. You can use this credit limit to use and test any Azure service and product for free completely. After 30 days this free trial account is disabled and you can not create or deploy new services.
Note: To register a new Microsoft azure account you will require Credit or debit card, its mandatory, very minimal charges will be deducted 2 INR or $1 while registration and after that no charges will be deducted without your knowledge (without upgrade). Credit or debit cards are used to verify your identity, and same card cannot be reused again after 30 days to register azure account with another email ID, Once free trial time period is over you can convert your azure account to Pay as you go and it will be charge billing at monthly basis.
Now the next question is how do you use Azure account for 12 months. Use link https://portal.azure.com/#blade/Microsoft_Azure_Billing/FreeServicesBlade to access your services after 30 days once your free trial expired. Those products are available on monthly basis for free. Again Microsoft has listed all its free azure services list on https://azure.microsoft.com/en-in/free/ and https://azure.microsoft.com/en-us/free/free-account-faq/.
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