From the naming of operating system only i.e Unix = Uniplexed Information and Computing Service vs Multics = Multiplexed Information and Computing Service, I was first having a misconception that the prime difference between Multics and Unix should be - Multics was Multi access to multi users by multi-programming whereas Unix is multi-* replaced by single. But later on I found that the coining of term Unix was just a pun on Multics. Actually both Multics and Unix can be considered as evolution of the early Time Sharing Systems.

I know that Ken Thompson and Dennis Ritchie started to write a simple system as an alternative to Multics in order to make it possible to run the system with lower hardware resources, which then become Unix.

I think talking about all differences between Multics and Unix would be too broad question. So, I would like to know the major significant technical difference between Multics and Unix.

Clarification (considering comments):

• By Unix, I mean the orginal Unix of 70s, not modern Unix or BSD
• Yes, the main difference is simplicity of Unix and I want to know what makes Unix simpler as compared to Multics
• If differentiating systems is broad, limit the difference between system kernels