This can speed you up by reducing the distance your hand has to travel. Trackball is a round ball, either on the keyboard or on the cover of the notebook to the right of the screen, that you roll with a fingertip. Notebook modems either come built into the notebook, or it's very common to have to add your own as an external option. The modem is the device that transmits data to and from your notebook so you can use email and the Internet. It is usually given as two numbers.
Some notebooks save weight and cost by leaving out the CD-ROM drive.
You can always buy an external drive separately. 6X, 10X, etc. If you use CDs primarily to install software, you'll be fine with whatever CD-ROM comes with your notebook. But it's a different story if you're into multi- media. If games, music, videos or movies are important, you'll need 32X, or higher speeds.