Linked from
The 10 pages that link to Network Time Protocol, each with the reason it gives.
SynchronizationRelated: It estimates network time offsets and adjusts computer clocks.
Unix timeRelated: Systems often convert synchronized clock readings into Unix timestamps.
Crystal oscillatorRelated: Accurate local clock references support reliable network timekeeping.
ChronometryRelated: It applies chronometric principles to keep distributed computer systems aligned.