An Ultrabook is a higher-end type of subnotebook defined by Intel. Intel has applied to register the name as a trademark. Ultrabooks are designed to feature reduced size and weight, and extended battery life without compromising performance. It uses low-power Intel processors with integrated graphics, solid-state drives for responsiveness, and unibody chassis to fit larger batteries into smaller cases. Because of their minimal size, the number of external ports (eg. USB) is limited.