MOTHERBOARD : known as the mainboard, system board etc is the main printed circuit board found in computers and other systems. It holds and allows communication between many of the crucial electronic components of a system, such as the central processing unit and memory, and provides connectors for other peripherals.
MICROPROCESSOR: is a computer processor that incorporates the functions of a computer’s central processing unit  on a single integrated circuit, The microprocessor is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and provides results as output.
MULTI-CORE PROCESSOR: is a single computing component with two or more independent actual processing units , which are the units that read and execute program instructions. Multi-core processors may have two cores, four cores , six cores, eight cores or more.
RANDOM-ACESS MEMORY(RAM) is a form of computer data storage. A  allows data items to be accessed (read or written) in almost the same amount of time irrespective of the physical location of data inside the memory. RAM is normally associated with volatile types of memory where stored information is lost if power is removed.
READ-ONLY MEMORY (ROM) is a class of storage medium used in computers and other electronic devices. Data stored can only be modified slowly, with difficulty, or not at all, so it is mainly used to distribute firmware . It is a non volatile memory 

POWER SUPPLY UNIT is an electronic device that supplies electric energy to an electrical load. The primary function of a power supply is to convert one form of electrical energy to another and, as a result, power supplies are sometimes referred to as electric power converters. Into a PC, PSU converts AC 230 volts into several DC voltages (Typically +12, -12, +5, -5, +3, -3…).
COMPUTER FAN is any fan inside, or attached to, a computer case used for active cooling, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heat sink to cool a particular component. 
AS PROCESSOR, graphics cards, RAM and other components in computers have increased in speed and power consumption, the amount of heat produced by these components as a side-effect of normal operation has also increased. These components need to be kept within a specified temperature range to prevent overheating, instability, malfunction and damage leading to a shortened component lifespan. 
GRAPHIC PROCESSING UNIT,  is a specialized electronic circuit designed to rapidly manipulate and alter memory to accelerate the building of images in a frame buffer intended for output to a display. Because of the large degree of programmable computational complexity for such a task, a modern video card is also a computer unto itself.

SOUND CARD is an internal computer expansion card that facilitates economical input and output of audio signals to and from a computer under control of computer programs. The term sound card is also applied to external audio interfaces that use software to generate sound, as opposed to using hardware inside the PC. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education and entertainment (games) and video projection. 
NETWORK INTERFACE CONTROLLER is a computer hardware component that connects a computer to a computer network. allows computers to communicate over a computer network, either by using cables or wirelessly.
HARD DISK DRIVE is a data storage device used for storing and retrieving digital information using one or more rigid (“hard”) rapidly rotating disks (platters) coated with magnetic material. The platters are paired with magnetic heads arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored or retrieved in any order rather than sequentially. HDDs retain stored data even when powered off.

inputs devices: mouse and keyboard ,KVM switch, digital video camara, microphone, scanner 2D-3D, miometric authentication device, touch screen, gamepad and joystick.
mouses can be: laser, wireless, glide pad, ergonomic, gamer, vocal, cerebral and footmouse.
keyboards can be: integrated, wireless, touch pad, illuminated and ergonomic.
output devices: speakers, headphones, screen, printer 
CD— 700mb DVD— 4.7 GB     BLUE-RAY —– 50GB AND 200GB      PENDRIVE— 2GB AND 256GB     SD—- 1GB AND 32 GB    MICROSD—-1GB AND 16 GB AND HDD— 1TB AND 2TB     1GB-1024MB  1TB-1024X1024MB
GIVE A PRESENTATION: no read, look every one, photos of good quality, short videos, move and gesticulate. rain at home, put examples…