Linus's Law states that: given enough eyeballs, all bugs are shallow
By shallow here, we mean found. If enough eyes look over a code change, eventually all code issues will be found and fixed.
The law was named in honour of Linus Torvalds, who is famous for creating the open-source Linux kernel.
The Linux kernel has around 27.8 million lines of code and by open-sourcing it (and allowing anyone to read it!) the aim is that all bugs and issues will be seen and fixed.
If you have ever been through code review of a large piece of work, sometimes something very obvious to someone else, was just totally forgotten by you. If we keep this trend going and allow hundreds of eyes to review, we stand a good chance of working out any issues asserts Linus's Law.