  The COUNT function returns the count of numeric values within a set of cells or values (includes numbers and dates) 
  The COUNTA function returns the count of nonblank values within a set of cells or values (includes numbers, dates, text values, logical values and errors) 
The Excel Count function returns the number of numeric values in a supplied set of cells or values. This count includes both numbers and dates.
The syntax of the function is :
Where the arguments, value1, [value2], etc, can be any values or references to cell ranges.
In Excel 2007 or 2010, you can enter up to 255 value arguments to the Excel Count function, each of which may consist of any number of cells or values. However, in Excel 2003, the function can only handle up to 30 arguments.
Numbers and dates are always counted as numeric values by the Excel Count function. However, text representations and logical values are counted differently, depending on whether they are supplied as a value in a range of cells, or if they are supplied directly to the function.
The table below summarises which values are and which are not treated as numeric values by the Excel Count function:
Value Within a Range of Cells 
Value Supplied Directly to Function 

Numbers  ARE counted  ARE counted 
Dates  ARE counted  ARE counted 
Logical Values  NOT counted  ARE counted 
Text Representations of Numbers & Dates 
NOT counted  ARE counted 
Other Text  NOT counted  NOT counted 
Errors  NOT counted  NOT counted 
The following spreadsheet shows several examples of the Excel Count function, with the values supplied to the function as one or more ranges of cells.
The spreadsheet on the left shows the formulas and the spreadsheet on the right shows the results.
Formulas:

Results:

Note, in the above example:
The following spreadsheet shows several examples of the Excel Count function, with the values supplied directly to the function.
Again, the spreadsheet on the left shows the formulas and the spreadsheet on the right shows the results.
Formulas:

Results:

Note, in the above example:
Further examples of the Excel Count function can be found on the Microsoft Office website.