What is the component of the processor that directs and coordinates most of the operations in the computer?

Imagine a computer system like an onion. It has many layers that play specific role in the overall design of a system. Computers normally perform simple tasks. But the combination of each layer plus the blinding speed that it does them allow a computer to perform more complex tasks.

Computer Systems / Information Systems
Computer hardware software, data and people which interact to solve problems and produce relevant information.

Computer Hardware
The physical elements of a computing system.

Computer Software
The programs that provide the instructions that a computer executes.

Layers of a Computing System (Inside - Out Approach)

Information - Reflects how information is represented on a computer. This refers to how binary becomes the basic unit of data representation for text, numbers, images, video, audio, etc.
Hardware - Includes devices, gates, circuits which control the flow of electricity in fundamental ways.
Programming - Deals with software and instructions for a computer to accomplish tasks and manage data. The main goal of programming is always: To solve problems
Operating System - Manages computer resources and the interaction between hardware, programs and data.
Application - Focuses on using the computer to solve specific real-world problems. 
Communication - Connection to networks (internal or external) to share information and resources. 

The System Unit (the computer case)

• The system unit is a case that contains electronic components of the computer used to process data. 
  
• Many computers today are very similar in terms of the components inside of them. These components generally include but not limited to - motherboard, processors, memory, power supply, drive bays, sound and video cards etc.
  

The Motherboard

• The motherboard is the main circuit board of the system unit. It helps integrate many of the components inside the system unit into one integrated circuit.
  

The Processor

• The processor, also called the central processing unit (CPU), interprets and carries out the basic instructions that operate a computer.
  
• The control unit is the component of the processor that directs and coordinates most of the operations in the computer 
  
• The arithmetic logic unit (ALU) performs arithmetic, comparison, and other operations
  
• For every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle: 1.FETCH - 2.DECODE - 3.EXECUTE - 4.STORE
  
• Most current personal computers support pipelining - this is when the processor begins fetching a second instruction before it completes the machine cycle for the first instruction.
  
• The processor contains registers, that temporarily hold data and instructions.
  
• The system clock controls the timing of all computer operations - (the pace of the system clock is called the clock speed, and is measured in gigahertz (GHz)
• A processor chip generates heat that could cause the chip to burn up - hence a fan or some form of cooling system is required to maintain normal temperatures of the processor chip.

• Parallel processing uses multiple processors simultaneously to execute a single program or task processors

Memory
Memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data. Stores three basic categories of items:

1. The operating system and other system software.
   
2. Application programs.
3. Data being processed and the resulting information.

Each location in memory has an address Memory size is measured in kilobytes (KB or K), megabytes (MB), gigabytes (GB), or terabytes (TB)

Adapter Card

Expansion Slot

Expansion Slots and Adapter Cards

• An expansion slot is a socket on the motherboard that can hold an adapter card
  
• An adapter card enhances functions of a component of the system unit and/or provides connections to peripherals
  

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Ports and Connectors

• Allows for various peripherals to be connected to the motherboard with a variety of purposes and uses.
  
• Standards are created by various technology consortiums in order to ensure better communication among various devices.
• However, there are several devices that may carry proprietary ports and connectors that are exclusive to a particular brand or product.
• Plug and Play protocols have allowed peripherals to be directly and immediately usable thus eliminating the installation of drivers.

Internal Bus

•  A collection of wires through which data is transmitted from one part of a computer to another. 
  
• You can think of a bus as a highway on which data travels within a computer. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory. 
  
• There's also an expansion bus that enables expansion boardsto access the CPU and memory.
  
• All buses consist of two parts -- an address busand a data bus. The data bus transfers actual data whereas the address bus transfers information about where the data should go.
  
• The size of a bus, known as its width, is important because it determines how much data can be transmitted at one time. For example, a 16-bit bus can transmit 16 bits of data, whereas a 32-bitbus can transmit 32 bits of data.