In this chapter, we review some historical understanding and recent advances on the Initial Mass Function (IMF) and the Core Mass Function (CMF), both in terms of observations and theories. We focus mostly on star formation in clustered environment since this is suggested by observations to be the dominant mode of star formation. The statistical properties and the fragmentation behaviour of turbulent gas is discussed, and we also discuss the formation of binaries and small multiple systems.

中文翻译：

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恒星质量分布和多样性的起源

在本章中，我们从观察和理论方面回顾了对初始质量函数 (IMF) 和核心质量函数 (CMF) 的一些历史理解和最新进展。我们主要关注星团环境中的恒星形成，因为观测表明这是恒星形成的主要模式。讨论了湍流气体的统计特性和破碎行为，我们还讨论了双星和小型多重系统的形成。