noun · the fundamental nature or central core of a concept, doctrine, or spirit

这种文化内核的核心是相互尊重。

noun · the hard central part of a fruit containing the seeds

这种李子的内核非常坚硬。

noun · the innermost part of a planet, especially the solid center of the Earth

地球的内核主要由铁和镍组成。

noun · the central component of a computer operating system that manages hardware and resources

由于内核错误，系统无法启动。