Median is a measure which is easy to understand and easy to determine. It is the halfway point in a data set and hence known as the positional average. Since it is not dependent on the actual values in the data set, it is less affected by extreme values. Against these merits, median is not based on all values and is not capable of algebraic treatments. It is also affected by sampling fluctuations.
Median is also a measure of position along with quartiles and Deciles. Median can also be understood as the second quartile or 50th percentile.

If the data values of a numerical data set is arranged in ascending or descending order of magnitude, the middle most item is called the median of the data set.

In numerical data distributions one half of the items are less than the median value and the other half is greater than the median value. The symbol used for median is MD.

Median Statistics
In the data set displayed above, the median is 7. It can be seen on either side of mean there are 6 values.