Newbie question on astrophotography

I keep seeing the beautiful time-lapse videos of the stars moving across the sky with a ton of detail like the milky way and such. How is this much detail picked up when you can't even see those types of details when watching the sky? I'm sure it's a dumb question but I can't figure it out. Thanks for the help!

That's because each and every individual frame are usually at least about 30 seconds duration.

Although your eyes might not see the detail, leaving the shutter open for "X" amount of seconds allows the sensor to collect more light (detail) then the human eye can see.