VLC is free software to play, transcode and broadcast video and audio files. It is cross-platform software that supports a large number of different formats and codecs.
A list of VLC features is available on the VLC website.
VLC is present on the main Debian repository:
apt install vlc
It's possible to launch VLC by double clicking on its icon, or directly with the command line:
It's also possible to play a file directly from the command line interface, for example:
Debian specific information
Debian specific limitations
Upstream specific information