A mid-range model is good for those people don’t want to spend a lot of money for their new laptop. A mid-range model weighs a few pounds less than a top range model and has a smaller monitor. A mid-range model may not be as fast as a top range model when you consider processor speed and the internal media options are more limited than in the high-range model. Lightweight models have the smallest display of all three also the slowest processor speeds. The facilities for expansion and built in drives are somewhat restricted and the media devices are usually on the external side. The main purpose of lightweight models is that more convenient to take along on account of their light weight and battery life is longer. For more info see notebooks computer