A content acquisition apparatus comprising: content storage means for storing content data; an output unit for outputting an identification of content data that is presented by a content providing apparatus for presenting content data; and a content acquisition unit for acquiring a piece of content data, which is identified by a content data identification selected by carrying out an operation to select one of identifications output by said output unit, from said content providing apparatus, wherein said output unit is arranged to output identifications of content data not yet stored in said content storage means in a format indicating that said content data have not yet been stored in said content storage means, and to output identifications of other content data already stored in said content storage means in another format indicating that said other content data have already been stored in said content storage means, the content acquisition apparatus being characterised in that: the content acquisition apparatus further comprises a list acquisition unit for acquiring, from said content providing apparatus, a presentable list, which is presented by said content providing apparatus as a list showing identifications of content data presentable by said content providing apparatus, wherein: said output unit is arranged to output said identifications of content data shown in the presentable list; said content data identification is an identification used for identifying a playlist including a plurality of pieces of content data; the content acquisition unit being further arranged to acquire a plurality of pieces of content data included in a playlist on the basis of the selected content data identification used for identifying said playlist by carrying out a batch process; and said batch process does not acquire content data already stored in said content storage means, even though said content data is included in said playlist. content storage means for storing content data; an output unit for outputting an identification of content data that is presented by a content providing apparatus for presenting content data; and a content acquisition unit for acquiring a piece of content data, which is identified by a content data identification selected by carrying out an operation to select one of identifications output by said output unit, from said content providing apparatus, wherein said output unit is arranged to output identifications of content data not yet stored in said content storage means in a format indicating that said content data have not yet been stored in said content storage means, and to output identifications of other content data already stored in said content storage means in another format indicating that said other content data have already been stored in said content storage means, the content acquisition apparatus being characterised in that: the content acquisition apparatus further comprises a list acquisition unit for acquiring, from said content providing apparatus, a presentable list, which is presented by said content providing apparatus as a list showing identifications of content data presentable by said content providing apparatus, the content acquisition apparatus further comprises a list acquisition unit for acquiring, from said content providing apparatus, a presentable list, which is presented by said content providing apparatus as a list showing identifications of content data presentable by said content providing apparatus, wherein: said output unit is arranged to output said identifications of content data shown in the presentable list; said content data identification is an identification used for identifying a playlist including a plurality of pieces of content data; the content acquisition unit being further arranged to acquire a plurality of pieces of content data included in a playlist on the basis of the selected content data identification used for identifying said playlist by carrying out a batch process; and said batch process does not acquire content data already stored in said content storage means, even though said content data is included in said playlist. said output unit is arranged to output said identifications of content data shown in the presentable list; said content data identification is an identification used for identifying a playlist including a plurality of pieces of content data; the content acquisition unit being further arranged to acquire a plurality of pieces of content data included in a playlist on the basis of the selected content data identification used for identifying said playlist by carrying out a batch process; and said batch process does not acquire content data already stored in said content storage means, even though said content data is included in said playlist.