Alternatively referred to as a notebook, a laptop is a portable computer that has most, or all, of the same abilities as a desktop, but is small enough for easy mobility. Portable computers run off AC power or batteries, such as NiMH, Nicad, or Li-ion packs, for several hours.
As you can see 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.
Tip: 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 on 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 America.
The first truly portable computer or laptop is considered to be the Osborne I, which was released on 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 US$1,795.
The IBM PC Division (PCD) later released the IBM portable in 1984, it's first portable computer that weighed in at 30 pounds. Later in 1986, IBM PCD announced it's 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.