When you think about hardware you are actually thinking about the parts of the computer that are tangible. So by hardware we mean the monitor, motherboard, CPU, RAM memory, video card, audio card, power supply, CD/DVD drive, hard disk, network card, keyboard, mouse, printer, scanner and other peripheral devices and expansion cards.

The monitor is and external display device which connects to the computer via a cable to a port on the video card. The port can be VGA or DVI. The monitor is the computer's way to communicate with the user, displaying result based on the user's instructions. Monitors can be based either on the Cathode Ray Tube (CRT) technology or the newer Liquid Crystal Display (LCD) technology.

The motherboard is a rectangular circuitry board that acts as a connector between the rest of the parts inside the computer case, like the CPU (Central Processing Unit), the disk drives (hard disk, CD, DVD and others), the RAM (Random Access Memory), the power supply and the various peripherals that connect to the ports and expansion cards.

The CPU or the processor is designed to carry out the various instructions received from the rest of the computer parts. It is considered to be the "brain" of the computer.

The RAM Memory comes in the form of integrated circuits that allow data to be stored and than retrieved regardless of the time it was deposited.  In other words the stored data can be retrieved randomly. RAM Memory is considered volatile (keeps data only as long as it is powered).

The video card (graphics card) is an expansion card that converts binary data from the processors into graphic data and outputs it through a cable to the monitor. The result is that images appear on the computer monitor. The video card is an output expansion card.

The audio card (sound card) is an expansion card similar to the video card. It converts audio signal received through a microphone into binary data and sends it to the CPU, and the binary data received from the CPU it converts into sound which is heard through speakers.

The power supply unit supplies electric power to the rest of the computer. It converts alternative current (AC) into low voltage direct current (DC) that the computer hardware component can use(with the exception of the computer monitor which takes it's own power separately from the rest of the computer hardware).

The CD drive is designed to be able to read from and/or write (burn) on compact discs (CDs). The DVD drive is similar to the CD-ROM drive, except it uses DVDs (Digital Versatile Disks or Digital Video Discs) as well as CDs. The CD and and the DVD are optical discs storage media formats. The CD/DVD drives can be ROM (Read Only Memory) which means that they can only read discs, RW which means that they can read and write on discs and also erase data on CDs/DVDs that support it.

The hard disk drive is a nonvolatile storage device (remembers data stored on it even when it is not powered) that stores the data that the user has direct access to. This includes the Operating System and programs installed files as well as other kinds of data (programs installation kits, music and video files, images etc.).

The network card can be either integrated on the motherboard or separate and provides access to the Internet or various computer networks. It has a unique MAC Address also called physical address. Network cards use Ethernet technology to provide access within Local Area Networks (LANs).

The keyboard is an external input device that is used by the computer user to sent various instructions to the computer. The mouse is also an external device that is used to further improve the user's access and management of the computer's resources and perform tasks.

The printer is an external device used to print text files or images. The scanner is used to input information into the computer by scanning different objects. Basically it creates an image which it sends to the computer. It can be visualized on the monitor with the help of certain programs capable of opening images.

Among the peripherals most commonly encountered are the computer speakers / headphones which play sounds with the help of the audio card, the microphone which you can use to input sounds into the computer and the webcam that is used to input video images into the computer.