I want to know the playback methods according to each backup type (SEC/AVI/DVR).

SEC can be viewed from a designated viewer (Samsung Viewer),
AVI can be played using regular media players such as the Windows Media Player.
DVR can be played from the DVR through backup search (cannot be played from a PC).

Hanwha Vision is the leader in global video surveillance with the world's best optical design / manufacturing technology and image processing technology focusing on video surveillance business for 30 years since 1990.