Recording medium, playback device, and playback method

A playback device, comprising:

• a readout unit that reads out data recorded in a recording medium;
• and
• a playback unit that plays the data that has been read out,
• wherein data including a digital stream file obtained by encoding video information is recorded in the recording medium,
• wherein a recording region of the recording medium has a first recording region where reading is performed at a first read rate, and a second recording region where reading is performed at a second read rate that is faster than the first read rate,
• wherein in a file system of the data, the data is classified into the digital stream file having real-time attributes and a data file having non-real-time attributes,
• wherein the data file read in during playback of the digital stream file is recorded in, of the first recording region and the second recording region, the same recording region where the digital stream file being played is recorded, and
• wherein the readout unit reads out the data without changing the first or second read rate when reading out the digital stream file and when reading out the data file.