basically, its made 4 customers satisfaction , and regar, 
ding their queries and give them appropriate feedback 
regarding their queries....

Call centers are normally contact centers, where a customer 
using a product or services of that company, seeks help 
through phone (voice) or mails (non-voice). This could be 
either a technical help or a non technical help that a 
customer may be seeking.
Call centers are mainly inbound and out bound. When the 
customer calls to seek help it is known as an inbound call, 
if the employee (consultant) calls customer to market or 
sell their product it is an out bound call. The same can be 
done thourgh mails. This is known as non-voice process. 
Mainly termed as BPO (Business Process Out Source.