COUNTIF:
Counts the number of cells within a range that meet the given criteria
The COUNTIF function counts the number of cells within a range that meet the given criteria. For
example, you can count all the cells that start with a certain letter, or you can count all the cells that contain a number
that is larger or smaller than a number you specify. For example, suppose you have a worksheet that contains a list of tasks
in column A, and the first name of the person assigned to each task in column B. You can use the COUNTIF function to count how
many times a person's name appears in column B and, in that way, determine how many tasks are assigned to that person.
COUNTIF takes
2 required arguments and
no optional arguments:
Syntax: COUNTIF(range,
criteria)
The arguments for the COUNTIF function are:
Argument

Required?

Description

range 
Required 
One or more cells to count, including numbers or names, arrays, or references that contain numbers. Blank and text values are ignored. 
criteria 
Required 
A number, expression, cell reference, or text string that defines which cells will be counted. For example, criteria can be expressed as 32, ">32", B4, "apples", or "32". 