Small, Discrete Components

• transistor - device that amplifies a signal or opens and closes a circuit
  
• integrated circuit (IC) - device made of semiconductor material; contains many transistors and performs a specific task
  
• resistor - device made of material which opposes the flow of electric current
  
• capacitor - electronic component that stores energy in the form of an electrostatic field; it consists of two conducting metal plates separated by an insulating material
  
• connector - the part of a cable that plugs into a port or interface
  
• light emitting diode (LED) - semiconductor device which emits light when a current passes through it
  

Personal Computer Subsystems

• printed circuit board (pcb) - a thin plate on which chips (integrated circuits) and other electronic components are placed
  
• CD-ROM drive – compact disk read only memory drive, a device that can read information from a CD-ROM
  
• CPU - central processing unit, the brains of the computer where most calculations take place
  
• floppy disk drive - a disk drive that can read and write to floppy disks
  
• hard disk drive - the device that reads and writes data on a hard disk
  
• microprocessor - a silicon chip that contains a CPU
  
• motherboard - the main circuit board of a microcomputer
  
• bus - a collection of wires through which data is transmitted from one part of a computer to another
  
• RAM - random access memory, also known as Read-Write memory, can have new data written into it as well as stored data read from it. A drawback of RAM is that it requires electrical power to maintain data storage. If the computer is turned off or looses power, all data stored in RAM is lost, unless the data was saved to disk
  
• ROM - read-only memory, computer memory on which data has been prerecorded; once data has been written onto a ROM chip, it cannot be removed and can only be read
  
• system unit - the main part of a PC; the system unit includes the chassis, microprocessor, main memory, bus, and ports, but does not include the keyboard or monitor, or any external devices connected to the computer
  
• expansion slot - an opening in a computer where a circuit board can be inserted to add new capabilities to the computer
• power supply - the component that supplies power to a computer
• EPROM - erasable programmable read-only memory (Retains information until exposed to ultra violet light.)

Backplane Components

• backplane - the large circuit board that contains sockets for expansion cards
  
• network card - an expansion board inserted into a computer so that the computer can be connected to a network
  
• video card - a board that plugs into a PC to give it display capabilities
  
• sound card - an expansion board that enables a computer to manipulate and output sounds
  
• parallel port - an interface capable of transferring more than one bit simultaneously and which is used to connect external devices such as printers
  
• serial port - an interface that can be used for serial communication, in which only 1 bit is transmitted at a time
  
• mouse port - a port designed for connecting a mouse to a PC
  
• power cord - cord used to connect an electrical device to an electrical outlet in order to provide power to the device