A laptop -  personal computer designed for mobile use and small and light enough to sit on a person's lap while in use.  A laptop integrates inside  the typical components of a desktop computer, like  a display, a keyboard, a pointing device ,a  speakers and a battery, into a single small and light pc. The rechargeable battery  is charged from an AC adapter and typically stores enough energy to run the laptop for three to five hours.

 Laptops  -  usually notebook with thicknesses between 15–40 mm) and dimensions  from 27x22cm, 13" display  to 43x31cm, 19" display).

Components - Computer hardware Miniaturization: a comparison of a desktop computer motherboard.

• Motherboard -  make and model specific. Board is a  small, highly integrated laptop may have no expansion slots at all, with all the functionality implemented on the motherboard itself; the only expansion possible in this case is via an external port such as USB. Other boards may have one or more standard, such as ExpressCard, or proprietary expansion slots. Other functions like  storage controllers,  sound card and external ports, networking  are builded on the motherboard.

• CPU (Central Processing Unit) – Laptop CPU's have advanced power-saving features and produce less heat than desktop processors. There is a wide range of CPU's designed for laptops available from AMD (Athlon, Turion 64, and Sempron) and   Intel (Pentium M, Celeron M, Intel Core and Core 2 Duo), Transmeta and PowerPC-based Apple laptops like  iBook and PowerBook, and others.

• RAM - Memory  –  They may be accessible from the bottom of the laptop for ease of upgrading, or placed in locations. Memory modules that are usually found in laptops are about half the size of desktop memory.  Currently, most midrange laptops are factory equipped with 3-4 GB of DDR2  RAM, while some higher end notebooks feature up to 8 GB of DDR3 memory. Netbooks however, are commonly equipped with only 1 GB of RAM to keep manufacturing costs low.

• Video display controller –  standard laptops the video controller is usually integrated into the chipset. This tends to limit the use of laptops for gaming and entertainment. Mobile graphics processors are comparable in performance to mainstream desktop graphic accelerator boards.

• EXPANSION CARDS –  PCMCIA  or ExpressCard  like Ethernet, Wi-Fi, or a  modem   usually accessible under an access cover on the bottom of the laptop. Two popular standards for such cards are MiniPCI and its successor, the PCI Express Mini. 

• BATTERY – Current laptops utilize lithium ion batteries, with models using the  lithium polymer technology. Typical battery life for standard laptops is two to five hours.