The terms "laptop" and "notebook" generally refer to similar devices of different sizes, so neither is inherently better. According to HowStuffWorks, laptops are usually larger than notebooks, which are in turn larger than netbooks.
There is no standard for naming mobile computers, so a computer that one manufacturer might call a laptop may be small enough to be considered a notebook by another. Smaller computers are lighter and are generally easier to carry around. Laptops, on the other hand, have larger screens, which makes watching videos and reading documents easier. Laptops also tend to have larger keyboards, making them more comfortable for typing.