What is data. analysis? Explain.

this is the process retrieve information from various kind of data.
lets take a example :- 
you have the data of sales of your product in various city. after analysis those data you find that there is a particular city where demand of your is less. then you will more analyse on data of that city, after proper analysing of all data you will get the actual problem to less demand of product. so now can know the exact problem and you can solve the problem. this will help your company to increase your demand. you can know the exact public demand and you can produce product on that demand.