Different types of call centers depend upon the requirements of the client and his business. For example, inbound call centers are centers that are used by customers to get answers to their queries and complaints. On the other hand, outbound call centers are mainly used by companies to promote their business by making welcome calls to existing and potential customers. Customers are informed about various products and services of the company. Similarly, there are domestic call centers to serve the customers in a particular country whereas there are also international call centers providing service to customers from various countries. There are also home based or virtual call centers that are operated through the web without the need to spend infrastructure in a physical call center.