A server which interacts with a display apparatus is provided. The server includes a storage unit configured to store conversation patterns for each service domain, a communication unit configured to receive a user's voice from the display apparatus, and a control unit configured to determine a service domain including the user's voice, generate response information corresponding to the user's voice based on a conversation pattern of the determined service domain, and to control the communication unit to transmit the response information to the display apparatus. When it is determined that a currently received user's voice is included in another service domain which is different from a service domain including a previously received user's voice, the control unit generates the response information corresponding to the currently received user's voice based on a conversation pattern of the other service domain.