It is a saving scheme specially designed for the parents of a girl child. The scheme was launched by Prime Minister Narendra Modi in January 2015, as a part of the Beti Bachao, Beti Padhao campaign.
Key Features:

The account can be opened at any post office or branches of authorised commercial banks.
Investment of minimum Rs 1000 and maximum Rs 1.5 lakh in a financial year. Subsequent deposits in multiple of Rs 100.
No limit on number of deposits either in a month or in a Financial Year.
A legal guardian/natural guardian can open account in the name of girl child.
A guardian can open only one account in the name of one girl child and maximum two accounts in the name of two different girl children.
Account can be opened up to age of 10 years only from the date of birth.
Partial withdrawal, maximum up to 50 per cent of balance standing at the end of the preceding financial year can be taken after account holder attaining age of 18 years.
Account can be closed after completion of 21 years.
Normal premature closure will be allowed after completion of 18 years, provided that girl is married.

Source: India Post