This indicates a high-definition resolution (1280x720 pixels) ripped from a digital high-definition source. While better than a "CAM" (theater recording), it is lower quality than a 1080p Blu-ray or 4K release.
A flexible video container format that can hold multiple audio and subtitle tracks. Where to Watch Legally
The file you're referring to, "," is a pirated version of the Marvel film distributed through unauthorized channels like Telegram. Movie Summary
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Based on the filename, here is what the technical specs typically mean: