The COUNTIF function in Microsoft Excel counts the number of cells within a range that meet a specified condition. It’s useful for quickly tallying entries that match specific criteria in your data.

 Basic Syntax

=COUNTIF(range, criteria)
 

- Range: The range of cells where you want to count the items.
- Criteria: The condition you want to apply (e.g., a specific number, text, or expression).

 Example Usage

1. Count Specific Text: Suppose you have a list of cities in cells A1:A10 and want to count how many times "New York" appears.
   
   =COUNTIF(A1:A10, "New York")
   

2. Count Numbers Greater Than a Value: If you have a list of scores in cells B1:B20 and want to count scores greater than 50.
   
   =COUNTIF(B1:B20, ">50")
   

3. Count Cells That Are Blank: To count empty cells in the range C1:C15.
   
   =COUNTIF(C1:C15, "")
   

4. Count Based on Cell Reference: If the criteria is in a cell (say D1) and you want to count how many cells match that value in E1:E10.
   
   =COUNTIF(E1:E10, D1)
   

5. Count with Wildcards:
   - Asterisk (): Matches any number of characters. For example, to count cells containing text that starts with "A" in range F1:F20:
   
     =COUNTIF(F1:F20, "A")
   
   - Question mark (?): Matches any single character. To count cells containing any three-letter word that starts with "A":
   
     =COUNTIF(F1:F20, "A??")
   

 Notes
- Criteria should be in quotes if it’s text or a logical expression (e.g., ">50").
- COUNTIF is case-insensitive, so "apple" and "APPLE" would both count the same.

Using COUNTIF makes it easy to apply quick data analysis within your Excel sheet. Let me know if you need further clarification on any examples!