Server for determining target device based on speech input of user and controlling target device, and operation method of the server

A server for controlling a device, among a plurality of devices in a network environment, based on a speech input, the server comprising:

• a communication interface configured to perform data communication;
• a memory storing a program comprising one or more instructions;
• and
• a processor configured to execute the one or more instructions of the program stored in the memory, to:
• receive a speech input of a user from at least one of the plurality of devices through the communication interface;
• convert the received speech input into text;
• analyze the text by using a first natural language understanding (NLU) model and determine a target device based on a result of analyzing the text;
• select, from a plurality of second NLU models, a second NLU model corresponding to the determined target device;
• analyze at least a part of the text by using the selected second NLU model and obtain operation information of an operation to be performed by the target device based on a result of analyzing the at least the part of the text;
• and
• control the communication interface to output the obtained operation information in order to control the target device based on the obtained operation information.