Abstract: A communication apparatus includes a connection unit that connects to a recording medium on which content data and management information about the content data are recorded, a communication unit that communicates with an external apparatus, and a control unit that, in a case where the communication apparatus has received a request for the management information about the content data from the external apparatus, reads out, in response to the request, the management information about the content data from the recording medium and controls the communication unit to transmit the read-out management information to the external apparatus, and reads out header information recorded in a header region of the content data from the header region and store the read-out header information.

Abstract: A communication apparatus that communicates with an external apparatus includes a connection unit that connects to a storage medium in which image data is recorded, and a control unit that, in a case where a request for a resized image of the image data is received from the external apparatus, generates a resized image by reading the image data from the storage medium in response to the request, controls transmission of the resized image to the external apparatus, and controls generating and temporarily storing metadata of the resized image.

Abstract: A communication apparatus capable of participating in a network formed by a relay apparatus, the communication apparatus includes a data communication unit configured to establish communication with a data processing apparatus via a first network, and perform data communication with the data processing apparatus, a reception unit configured to receive a notification indicating whether the data processing apparatus has formed the first network as the relay apparatus, from the data processing apparatus, and a control unit configured, if a notification indicating that the data processing apparatus has formed the first network as the relay apparatus is received by the reception unit, to perform control to restrict transmission or reception of data via an Internet.