以下是 Ultrabook 的 WIKI定义
An Ultrabook is a higher-end type of subnotebook defined by Intel. Ultrabooks are designed to feature reduced size (less than 2.1 cm thick) and weight (usually less than 1.5 kgs) without compromising performance and battery life. They use low-power Intel processors with integrated graphics, and unibody chassis to fit larger batteries into smaller cases.[1] Some models have limited external ports (e.g. USB)[2] due to their extremely thin profile.