Some videos are obviously more than an hour, how can the player only display for tens of seconds?

It seems to be a video edited by nonlinear editing software, such as a video with a duration of several minutes or dozens of minutes ~ After editing the timeline, it is only displayed as ten seconds or dozens of seconds, but the original duration is played. On the other hand, it is also possible to change the original video, which is only a few minutes long, into tens of minutes or an hour long, and the time can be modified at will, but the duration of the original video remains unchanged, only the progress time you see has changed.