Get nth highest and lowest salary of an employee

One student of me asked "how can we get nth highest and lowest salary on an employee ?". In this article I am going to expose, how can we achieve this in SQL Server.

Suppose we have employee name and salary as shown in below fig.

Query to get nth(3rd) Highest Salary

 Select TOP 1 Salary as '3rd Highest Salary' 
from (SELECT DISTINCT TOP 3 Salary from Employee ORDER BY Salary DESC) 
a ORDER BY Salary ASC 

Query to get nth(3rd) Lowest Salary

 Select TOP 1 Salary as '3rd Lowest Salary' 
from (SELECT DISTINCT TOP 3 Salary from Employee ORDER BY Salary ASC) 
a ORDER BY Salary DESC