A computer is made up of different components like the motherboard, processor, display, RAM, etc. Each component has to do its own set of jobs in coordination with other components to make the computer work correctly. The basic building block of a laptop is a green colored printed circuit board called Motherboard. All the other components are connected to it and use various circuits and interfaces to communicate with each other.
Central Processing Unit
The microprocessor, or CPU, works with the operating system to control the computer. It essentially acts as the computer's brain. The CPU produces a lot of heat, so a desktop computer uses circulating air, a fan and a heat sink -- a system of plates, channels and radiator fins used to draw heat off of the processor -- to cool off. Most modern CPUs are microprocessors, meaning they are contained on a single integrated circuit (IC) chip. An IC that contains a CPU may also contain memory, peripheral interfaces, and other components of a computer; such integrated devices are variously called microcontrollers or systems on a chip (SoC). Some computers employ a multi-core processor, which is a single chip containing two or more CPUs called "cores"; in that context, one can speak of such single chips as "sockets".
Memory
A laptop's memory can make up for some of the reduced performance that comes from a slower processor. Some laptops have cache memory on or very near the CPU, allowing it to access data more quickly. Some also have larger busses, allowing data to move between the processor, motherboard and memory more quickly. Laptops often use smaller memory modules to save space. Memory types used in laptops include:
Small Outline Dual Inline Memory Module (SODIMM)
Dual Data Rate Synchronous RAM (DDR SDRAM)
Single data rate Synchronous RAM (SDRAM)
Proprietary memory modules Some laptops have upgradeable memory and feature removable panels for easy access to the memory modules.
Drives
A permanent storage space which is used to keep all the data required by a computer like the operating system files, songs, videos, and third-party software files, etc. When needed, the data is transferred from the hard drive to the random access memory for being used by the CPU.
Most laptops can contain a single 2.5-inch drive, some laptops support a hybrid mode, combining a 2.5-inch drive, typically a spacious HDD for data, with an mSATA or M.2 SDD drive, typically having less capacity, but a significantly faster read/write speed. The operating system partition would be located on the SSD to increase laptop I/O performance.
Another way to increase performance is to use a smaller SSD of 16-32 GB as a cache drive with a compatible OS. A variety of external HDDs or NAS data storage servers with support of RAID technology can be attached to virtually any laptop over such interfaces as USB, FireWire, eSATA, or Thunderbolt, or over a wired or wireless network to further increase space for the storage of data.
Many laptops also incorporate a card reader which allows for use of memory cards, such as those used for digital cameras, which are typically SD or microSD cards. This enables users to download digital pictures from an SD card onto a laptop, thus enabling them to delete the SD card's contents to free up space for taking new pictures.
Graphics & Sound
On most laptops a graphical processing unit (GPU) is integrated into the CPU to conserve power and space. This was introduced by Intel with the Core i-series of mobile processors in 2010, and similar accelerated processing unit (APU) processors by AMD later that year A graphics card, or a GPU, or a visual processing unit (VPU) takes care of the graphics department of the computer. It processes the relevant data which is to be displayed on the monitor. GPUs can be integrated directly into the motherboard. They also come with separate graphics processors which can be connected to a computer using the PCI slot present on its motherboard.
Most laptops also have sound cards or integrated sound processing on the motherboard as well as small, built-in speakers. However, there is generally not enough space inside a laptop for a top-of-the-line sound card or a high-quality speaker. Gaming enthusiasts and audiophiles can supplement their laptops' sound capabilities with external sound controllers, which use USB or FireWire ports to connect to the laptop.
Cooling System
Laptops rely on heat pipes to rapidly move waste heat towards the edges of the device, to allow for a much smaller and compact fan and heat sink cooling system. Waste heat is usually exhausted away from the device operator towards the rear or sides of the device.
It is believed that some designs with metal cases, like Apple's aluminum MacBook Pro and MacBook Air, also employ the case of the machine as a heat sink, allowing it to supplement cooling by dissipating heat out of the device core.
Secondary device temperature monitoring may reduce performance or trigger an emergency shutdown if it is unable to dissipate heat, such as if the laptop were to be left running and placed inside a carrying case. Aftermarket cooling pads with external fans can be used with laptops to reduce operating temperatures.
Networking
A wireless adapter is a device that adds wireless connectivity to a laptop or desktop computer. All of the adapters below are available as external USB modules as well as PCI or PCI Express (PCIe) cards that plug into an empty slot on the motherboard. Wi-Fi adapters provide connectivity to the local area network (LAN) in the home or office.
Cellular (3G, 4G) Cellular wireless adapters, also called "cellular modems," "air cards," "broadband adapters" or "broadband cards," deliver the same 3G and 4G wireless service that smartphones use.
Battery
A laptop's battery is charged using an external power supply which is plugged into a wall outlet. The power supply outputs a DC voltage typically in the range of 7.2—24 volts. The power supply is usually external, and connected to the laptop through a DC connector cable. In most cases, it can charge the battery and power the laptop simultaneously.
When the battery is fully charged, the laptop continues to run on power supplied by the external power supply, avoiding battery use. The battery charges in a shorter period of time if laptop is turned off or sleeping. The charger typically adds about 400 grams (0.88 lb) to the overall transporting weight of a laptop, although some models are substantially heavier or lighter. Most 2016-era laptops use a smart battery, a rechargeable battery pack with a built-in battery management system (BMS).
Electronic Visual Display
Is an output device connected to a computer which displays the desired graphics output produced by the graphics processing unit of the computer. Generally known as a monitor, a computer display can be an LCD (Liquid Crystal Display) based or LED (Light Emitting Diode) based.
The computer can connect to the display via different connection modes like VGA, HDMI, DVI, DisplayPort, etc. Intel’s Thunderbolt offers video output as well as data transfer through the same connection interface for different devices.
Bios
(Basic Input Output System) A set of routines residing in firmware that boots the operating system and sets up the hardware in an x86-based PC. Prior to loading the operating system, the BIOS provides software drivers for the basic peripheral support that is part of the motherboard, including the keyboard, mouse, monitor and hard disk.
The drivers enable the user to edit configuration settings and allow the hardware to boot from the hard disk or other storage device. After the operating system is loaded, more elaborate drivers are typically loaded, which replace the BIOS routines. The BIOS also supports internal services such as the real-time clock (time and date). The BIOS Sets Up the Computer On startup, the BIOS tests the system and prepares the computer for operation based on the installed hardware and the configuration settings from the manufacturer and user.
