Start with four separate questions
Which movie is it? What resolution does the edition provide? Which audio and subtitle tracks are included? Can your player handle it? A filename may mix all four answers, but one label cannot answer them all.
Container and codec
MKV is the Matroska container format. It can hold different media tracks and information about them. MP4 is another container. A codec is the method used to encode a video or audio track. Recognising a container does not mean a device supports every codec that might appear inside it.
Resolution and size
720p and 1080p identify different picture resolutions. File size depends on more than resolution, including length, bitrate, compression and included tracks. A longer movie can be larger without having a sharper image. A very small version may sacrifice detail, especially in visually busy scenes.
Language choices
Look for named audio and subtitle tracks. “Dual audio” does not automatically specify Hindi and English, and an MKV extension does not promise subtitles. The available tracks belong to that particular edition.
For viewing services reached from our pages, use their supported players and displayed edition details. You can consult the Matroska specification for the format's technical structure, or return to HD and 4K help for a simpler picture-quality checklist.