A display apparatus comprising: a first communication unit configured to communicate with a server to receive an interaction request for a user of the display apparatus from one or more other users using other display apparatuses (100-2, 100-3) communicatively coupled to the server; a second communication unit configured to communicate with an external apparatus configured to provide first content to the display apparatus; a display configured to display first content received from the external apparatus or second content from other sources different from the external apparatus; and a controller configured to: control the second communication unit to transmit a first signal to the external apparatus, to turn off the external apparatus when the second content is displayed on the display, control the display to display a User Interface UI on an area of the display in response to receiving the interaction request from the server in a state in which the display displays the second content, and control the second communication unit to transmit a second signal to the external apparatus, to turn on the external apparatus, in response to receiving an instruction from the user of the display apparatus to accept the interaction request on the UI, wherein the interaction request received from the server includes a request to display the first content provided by the external apparatus on the display. a first communication unit configured to communicate with a server to receive an interaction request for a user of the display apparatus from one or more other users using other display apparatuses (100-2, 100-3) communicatively coupled to the server; a second communication unit configured to communicate with an external apparatus configured to provide first content to the display apparatus; a display configured to display first content received from the external apparatus or second content from other sources different from the external apparatus; and a controller configured to: control the second communication unit to transmit a first signal to the external apparatus, to turn off the external apparatus when the second content is displayed on the display, control the display to display a User Interface UI on an area of the display in response to receiving the interaction request from the server in a state in which the display displays the second content, and control the second communication unit to transmit a second signal to the external apparatus, to turn on the external apparatus, in response to receiving an instruction from the user of the display apparatus to accept the interaction request on the UI, wherein the interaction request received from the server includes a request to display the first content provided by the external apparatus on the display. control the second communication unit to transmit a first signal to the external apparatus, to turn off the external apparatus when the second content is displayed on the display, control the display to display a User Interface UI on an area of the display in response to receiving the interaction request from the server in a state in which the display displays the second content, and control the second communication unit to transmit a second signal to the external apparatus, to turn on the external apparatus, in response to receiving an instruction from the user of the display apparatus to accept the interaction request on the UI, wherein the interaction request received from the server includes a request to display the first content provided by the external apparatus on the display.