OPTICAL DISK, AND INFORMATION RECORDING/REPRODUCTION APPARATUS

摘要

In an optical disk having a recording plane with a spiral first track and a spiral second track, information being recorded into and/or reproduced from said first and second tracks, the first track is formed in a groove-like shape, the second track is formed between adjacent first tracks and in a land-like shape, and information is recorded in the first and second tracks in different modulation methods.