How are layers of sedimentary rock like a time machine? ?

The layers of a sedimentary rock can be very clear and show what type of rock was there in that time period. It can also show major geological events that happened, so it is very like a time machine in the sense that it tells you a lot about the past.

Cause every layer is from different timelines it's sorta like a time machine.
(at least in my opinion it's sorta like a time machine)