A thin and light notebook computer usually has a standard size, such a 13"-15", and is built in such a way as to cut down on weight and lower the profile. Traditionally these notebooks did not have CD/DVD drives, but in recent years advances in technology have allowed them to be included on most models. Ultraportables are even smaller, and will usually have screens that are 8" and under. They come in many form factors from a standard notebook style to innovative designs that use slide out keyboards.