Which of the following is NOT a portable device

Desktop computers are not considered portable devices because they are large and require external power sources. In contrast laptops thumb drives and iPods can easily be carried and used in different locations. Portability is an important feature for modern technology because users need access to data and applications while moving from place to place. Devices like laptops combine power and mobility allowing people to work study or entertain themselves anywhere. Thumb drives and iPods are examples of small devices that provide convenience for data transfer and media use. Thus desktops are stationary systems while others are portable.