In simple terms, outsourcing call centers oversee call center functions that were once undertaken in house by a business enterprise. For example, historically most businesses that dealt with the public included in house customer service centers. Customers were able to call the customer service staff with questions, concerns and problems. The costs associated with running an in house customer service center ended up being expensive in many instances. Indeed, over time for some companies and businesses, the costs associated with running an in house customer service center became prohibitive.

Many outsourcing call centers handle customer and client service calls. There are outsourcing call centers that handle these types of customer or client service calls for a number of different businesses. On the other hand, there are outsourcing call centers that will handle the customer service work for only one business enterprise.

There are also outsourcing call centers that handle marketing and sales functions that previously were handled in house. These outsourcing call centers can take three forms. First there are outsourcing call centers that will handle calls from people who are calling in to place orders,

Second, there are outsourcing call centers that will handle the process of returning calls to people who have responded to a solicitation online or in the brick and mortar world.

Finally, there are outsourcing call centers that do different types of sales calling - including, in some instances, cold calling. Again, these are all functions that at one point in time were handled internally and in house be a business.