COUNTIF if used to count the numbers of cells that meet a given criteria within a specified range. The COUNTIF Formula will help you to Count all the cells containing a selected value or criteria. It counts all the cells that satisfy particular criteria. For example in a class of about 15 students you want to know the number of students below the have the same score in some subject and you want to determine the number of students. To do this you type COUNTIF and select it.
In this case we want to find the number of students with 70marks in the table.The range are the cells with figures in this instance it might be text or expressions in other instances and the criteria is the value(70) for which you want to find the students that have it.
In this case the answer is 5. This means that 5 students have 70marks in the table.