DVD Players Game ("DVD-PG", "DVDPG") is the term used in Japan for adult games that are played on DVD Players (or consoles/systems capable of DVD play-back).
DVDPGs began appearing in 2000, released by eroge makers and adult video producers, although a unified terminology was not set until 2001 by the EOCS. While most DVDPG titles are ports of PC games, in recent years original DVDPG games have been appearing.
Compared to PC games, DVDPGs have very limited controls, and have very limited capability for stats/flag management. Thus most DVDPGs are of the simple ADV and Visual Novel genres.
The all-age counterpart to DVDPG is "Interactive DVD" in Japan (and DVD TV game in the US). However, the usage of the term "interactive DVD" is not just limited to games, but is also applied to any DVD movie featuring various different levels of user input/feedback.
this article is partially based on the Japanese Wikipedia article DVDプレイヤーズゲーム