How to do Data analysis in Oracle SQL using analytical functions

Analytic functions in Oracle can be defined as functions similar to aggregate functions (Aggregate functions is used to group several rows of data into a single row) as it works on subset of rows and is used to calculate aggregate value based on a group of rows but in case of aggregate functions the number of rows returned by the query is reduced whereas in case of aggregate function the number of rows returned by the query is not reduced after execution.
Data analysis is the most essential in today's business world. We need to know every details from customer's requirement to modern trends. What product we will bring to market, price of the product everything depends on data analysis. So in this tutorial I have tried to start with simple data analysis on attendance and salary of employees.