intro to computers computer applications. what is a computer? initially the term computer referred...
TRANSCRIPT
Intro to Computers
Computer Applications
What is a Computer?
• Initially the term computer referred to an individual whose job it was to perform mathematical computations.
• Today, it refers to an electronic device that accepts data (input), then processes that data producing information (output).
What is a Computer
• A computer is just a machine. It does not think thus has no intelligence. It only knows what we tell it. It follows our instructions precisely.
Information Processing Cycle
• We use computers as a tool to assist users in converting data into information.
• User: Anyone who communicates with a computer or uses its information
• Data: Raw facts, figures, numbers, words, images
• Information: data that has been processed into a form that is more meaningful & useful
Information Processing Cycle
Information Processing Cycle
• The computer’s hardware operates under detailed sets of instructions, software, that control every aspect of its operation.
• Hardware: a computer’s electronic and mechanical equipment
• Software: instructions that tell the hardware how to perform
Information Processing Cycle
• Software controls:
– How the screen appears– How to accept the user’s commands– How commands are interpreted & executed
– How the output is to be presented
Information Systems
• The computer’s hardware and software work together to form an information system.
Information Systems
• Primary components1. People2. Input Devices 3. System Unit4. Output Devices5. Communication Devices6. Storage Units7. Software
• People input data into the computer and receive the processed information.
Input Devices
• These are devices that allow users to enter data and instructions.
• Primary input devices include:– Keyboard– Mouse– Microphone– Scanners– Digital cameras
Output Devices
• Output Devices convey information to the user.
• Primary output devices include:– Monitors– Printers– Speakers
System Unit
• The case containing the internal components.
• The System Unit is composed of two primary parts: 1. The Central Processing Unit (CPU)
2. Main Memory or RAM
Central Processing Unit
• The CPU contains the circuitry that interprets and carries out the basic instructions that operate the computer.– It is known as the “brain” of the computer.
• The CPU is designed into a chip, often referred to as the microprocessor.
Central Processing Unit
• The CPU is comprised of two parts:
– The control unit• Controls the signal between the ALU, Main Memory, & the input/output devices
– The arithmetic logic unit (ALU)• Performs all arithmetic & logical operations
Main Memory
• Main Memory or Random Access Memory (RAM)
• RAM is a buffer where all data must be temporarily stored before processing.
• Main Memory is measured in megabytes.
Main Memory• Together, the CPU and the RAM make up the computer’s system unit and help dictate a computer’s capacity.
• The more instructions the CPU processes per second, the faster information can be processed.
• The more memory a computer contains, the more information can be stored and the faster information can be processed.
Which would be faster
Computer 1512MB RAM
Computer 21000MB RAM
Hard Drive
• “Long-term Memory”
• A hard drive stores a computer’s written data and information.
Storage Units
• Storage Units provide permanent storage for both software and data.
• Primary storage devices include:– Floppy Disks– Zip Disks– CD-Roms– Hard Disks– USB Flash Drives
Software
• Software provides the instruction sets needed by a computer.
• Computers use two types of software:1. Application Software
2. System Software
Software
• Application Software– Software designed to perform specific tasks.
Software
• System Software– Controls the operation of the computer and
its devices.
– It is the interface between the user, applications and hardware.
– There are two types of system software:
1. Operating System (Windows)
2. Utility Programs (Virus Scan, Volume Control)