The document discusses ultrabooks, a type of subnotebook computer promoted by Intel beginning in 2011. Ultrabooks are designed to be thin, lightweight laptops with a screen size of less than 15 inches and weight of less than 2 kg. They utilize Intel's Consumer Ultra-Low Voltage processors and solid state drives to provide portability, battery life, and computing power without sacrificing performance. While offering benefits, ultrabooks also face limitations including durability, utility, and higher costs. Major manufacturers of ultrabooks include Acer, HP, Lenovo, LG, Toshiba, Samsung, and Lenovo.