IFNA is a function in Google Sheets that helps to handle errors in a spreadsheet. It checks if a given value is an error or "#N/A" (which stands for "not available") and returns a specified value instead of the error value.

The syntax for the IFNA function is as follows:

IFNA(value, valueifna)

The 'value' parameter is the value or expression to check for an error value. The 'valueifna' parameter is the value to return if 'value' is an error or "#N/A". If 'value' is not an error, then the IFNA function returns the value of 'value'. If 'value' is an error, then the IFNA function returns the value specified in 'valueifna'.

Using the IFNA function can help make your spreadsheet calculations more accurate and prevent errors from propagating through your calculations.