If I want to check the standard deviation of a price for the past 20 bars, what is the difference between MA shift and shift?

double iStdDev( string symbol, int timeframe, int ma_period, int ma_shift, int ma_method, int applied_price, int shift)Calculates the Standard Deviation indicator and returns its value. Parameters:

double iStdDev( string symbol, int timeframe, int ma_period, int ma_shift, int ma_method, int applied_price, int shift)Calculates the Standard Deviation indicator and returns its value. Parameters:

**symbol**- Symbol the data of which should be used to calculate indicator. NULL means the current symbol.**timeframe**- Timeframe. It can be any of Timeframe enumeration values. 0 means the current chart timeframe.**ma_period**- MA period.**ma_shift**- MA shift.**ma_method**- MA method. It can be any of Moving Average method enumeration value.**applied_price**- Applied price. It can be any of Applied price enumeration values.**shift**- Index of the value taken from the indicator buffer (shift relative to the current bar the given amount of periods ago).