Recording and/or reproducing apparatus, portable recording and reproducing apparatus, data transfer system, data transfer method, and data recording and reproducing method

A recording/reproducing apparatus comprising:

• recording/reproducing means for recording/reproducing data to/from a rewritable recording medium having a data area in which data are stored and a management data area in which management data for managing said data are stored;
• selecting means for selecting group management data to be stored in said rewritable recording medium in accordance with a user operation, said group management data being stored in said management data area for managing as a data group a plurality of data to be stored in said data area;
• reading means for reading said selected group management data and said data group managed by said group management data;
• and
• transfer means for transferring said group management data and said data group read by said reading means to an external apparatus, wherein said recording/reproducing means rewrites said group management data stored in said management data area of said rewritable recording medium in response to said transfer operation.