"Fixed Deposit Account" is a name used in South African, Indian, and several other markets for the same underlying product covered on this wiki under Fixed Deposits: a savings deposit in which a customer commits a lump sum to a bank for a fixed term, in exchange for a guaranteed, typically higher, interest rate than an ordinary savings account offers, with early withdrawal generally restricted or subject to a penalty.
Rather than duplicate the full explanation across two separate pages, the detailed discussion of how fixed deposits work, the typical range of terms and rates offered, and the penalties for early withdrawal, is covered on the main Fixed Deposits entry, which readers encountering "Fixed Deposit Account" in a South African, Indian, or similar source should refer to for the full explanation.
In short: if a source refers to a "Fixed Deposit Account," it is describing exactly the same product as the Fixed Deposits entry on this wiki, a lock-in term deposit paying a fixed rate in exchange for committing funds for a set period.