Alternatively referred to as a notebook, a laptop is a portable computer that is more efficient, and nearly as powerful, as a desktop computer. Portable computers run off AC power or batteries, such as NiMH, NiCad, or Li-ion packs, for several hours.
As shown in the picture, the Dell Latitude D610 notebook has everything needed for normal operation. It has an LCD screen, keyboard, and touchpad. Although a laptop may have multiple external devices and cables connected to it, no external connections are required for standard usage.
A laptop is not spelled as "labtop," "lab top," or "lap top."
The first laptop or portable computer
The IBM 5100 is the first portable computer, which was released in September 1975. The computer weighed 55-pounds and had a five inch CRT display, tape drive, 1.9 MHz PALM processor, and 64 KB of RAM. In the picture is an ad of the IBM 5100 taken from a November 1975 issue of Scientific American.
The first truly portable computer or laptop is considered to be the Osborne I, which was released in April 1981 and developed by Adam Osborne. The Osborne I weighed 24.5-pounds, had a 5-inch display, 64 KB of memory, two 5 1/4" floppy drives, ran the CP/M 2.2 operating system, included a modem, and cost $1,795.
The IBM PCD (PC Division) later released the IBM portable in 1984, its first portable computer that weighed 30-pounds. Later in 1986, IBM PCD announced its first laptop computer, the PC Convertible, weighing 12-pounds. Finally, in 1994, IBM introduced the IBM ThinkPad 775CD, the first notebook with an integrated CD-ROM.
The first Apple laptop, the Macintosh Portable, was released in September 1989. Due to its size and cost (roughly $6500), it was not very popular. Apple changed their approach to laptop development and, in October 1991, released the PowerBook line of laptops. They released the PowerBook 100, PowerBook 140, and PowerBook 170, which were more well received in the computer market.