— PC design has a drive for working with optical CDs and DVDs (CD-only drives are considered obsolete and are almost never used). Usually, besides reading, the ability to write to such disks is provided. The standard capacity of a DVD is 4.7 GB (more is possible); this allows recording a high-resolution movie onto a single disk and installation files of a rather “heavy” modern game onto several discs. At the same time, DVD drives and media for them are cheaper than Blu-ray, and therefore are used more often.
