What is mean? Is mean and average are same?

The mean is the average of the numbers: A calculated "central" value of a set of numbers. 

To calculate the mean, just add up all the numbers, then divide by how many numbers there are. 

Example: what is the mean of 2, 7 and 9? 

Mean=(2 + 7 + 9) ÷ 3 = 18 ÷ 3 = 6

Both have the same meaning.