Method and apparatus of reproducing data recorded on recording medium and local storage

An apparatus for reproducing data from a computer readable medium, the apparatus comprising:

• a pick-up unit configured to read first data recorded on the computer readable medium;
• a local storage configured to store second data associated with the first data, the second data including a stream file;
• and
• a decoder configured to decode the first data and the second data using a PlayList file which includes a main path and a sub path,
• wherein the main path includes at least one PlayItem for play-back of the first data, and the sub path includes at least one SubPlayItem associated with the PlayItem for play-back of the second data in association with the play-back of the first data, and the Playitem includes a stream information table (STN table) field defining stream information of the first data and the second data.