Answering service
Companies that use an answering service outsource the answering of incoming telephone calls. If possible, callers are transferred to an employee of the outsourcing organization. Optionally, call centers offering this type of service can also answer simple questions, using an FAQ or call script.
Possible arguments for hiring an answering service are the desire to be better reachable by telephone and to handle fewer telephone calls yourself. By hiring an external answering service there is no need to hire your own operators. Most answering services work with a billing model based on the number of calls made.