1.Manual switching system requirement human operator.But later on strowger invented automatic switching system where human operator don’t exist. 2. In a manual exchange the subscriber needs to communicate with the operator. 3.In automatic switching system calling privacy is secure.Establishment and release of calls are faster in automatic exchanges. 4.In automatic switching system there is a pulse numbering system. 5.In manual switching system connections were made by the operators at the telephone exchanges in order to establish.