You could have an actor say something incoherent and implausible (employing something like Star Trek's technobabble). This works if "how it works" doesn't matter one whit to the story. You can have your characters simply talk about the Turbo Encabulator and move on.
Conversely, you could make your movie about the incomprehensible nature of time travel, and simply talk in technical terms without regard for your audience. Feeling lost is part of the experience (a la Primer).
But many films walk somewhere in-between these two extremes.
This is where a simple visual analogy can work wonders. Have a character more in-the-know than your protagonist or curious bystander explain the situation to a four year old. Not literally. But what picture could you show a child that would help the kid grasp the situation? Find that, and your audience can follow along.
Example: Your characters have just managed to survive a harrowing trip through a jungle with robots or monsters or aliens in pursuit. The small band has made it into an ancient temple. There is a pause in the action.
Tom: Is this real?
Sam: Real enough.
Tom: So we're in a computer, like Tron or the Matrix?
Sam: Those were separate worlds. This one is more...
Here he interlinks his fingers.
And the audience understands.
Your Media Production Mentor