A server includes a memory storing instructions and a processor configured to execute the instructions to obtain an inside-fridge image captured in a refrigerator by comparing a pre-stored image to the obtained inside-fridge image, identify whether a change area in which a change occurred in the obtained inside-fridge image is present in the obtained inside-fridge image, based on the change area being not present in the obtained inside-fridge image, obtain first food storage information, using a first result of recognizing the pre-stored image, based on the change area being present in the obtained inside-fridge image, obtain second food storage information, using the obtained first food storage information and a second result of recognizing an object included in the obtained inside-fridge image, and transmit, to the refrigerator, the obtained inside-fridge image and either one or both of the obtained first food storage information and the obtained second food storage information.