Diffen › Technology › Computers
A laptop computer, or simply laptop is a small mobile computer, which usually weighs 2-18 pounds (around 1 to 8 kilograms), depending on size, materials, and other factors. Laptops were developed to get in the portability factor with the computers. The initial laptops were more or less of same configurations as a desktop. But the demand for the size reduction made them more 'lap'py.
A Notebook is an extremely lightweight personal computer. Notebook computers typically weigh less than 6 pounds and are small enough to fit easily in a briefcase. Notebooks were designed to get the frequently used functionalities of a computer in a handy size and easy to carry case. The handy notebook size was the one that defined notebook computers. There was not even a replaceable hard disk or other peripherals associated with them initially."
-- So, basically they are the exact same. ...Perhaps the Notebook being smaller (book size), and the Laptop being larger (put it on the 'top' of your 'lap').
"Chromebook"? ...Is that any different than an Ipad?