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2.1. Introduction to Computers

What is a computer?

Definitions

A computer is a machine that manipulates data according to a list of instructions called a program.

basic computer processes
By Paul Mullins: constructed image

A computer can also be defined as an electronic machine that accepts input (data), processes it and gives out results (information). A program or app (short for application program) in memory manages the processing. It can make use of data or information stored in memory and remember the results of the processing for later use, again in memory.

A computer is also a (fairly complicated) tool intended to assist the user in accomplishing information-based tasks ranging from locating and acquiring data/information to to processing it to presenting or transmitting it.

In addition, it is an entertainment center allowing the user to browse the web, read a book, play a video game, watch a movie, etc. These devices (and the following) are often left out of the definition of a computer because they are not "general purpose" computing devices, that is, a Kindle (tm) is used to read books, but not to create a classroom presentation. They are included here because the lines separating such devices are becoming blurry.

In certain specialized instances, such as embedded real-time computers (as found in your car or microwave), it is part of a more complex tool or device.

In a sense, a computer is ultimately a simple, generic device that can be used to accomplish a wide variety of tasks. This leads to the first two generic definitions provided above.

A Computer-based system [src]

A computer-based system is a system in which a computer is involved and consists of three major elements: Hardware, Software, and User (where the user may be another computer system). The elements of a computer based system are described in the three following scenarios:

  1. Patient monitoring system
    Hardware
    Electrode leads, Micro computers, Network platform, and a Server Computer
    Software
    Monitoring Application, Database, and Operating System
    User
    Medical staff, Administrators
  2. Controlling a section of an Assembly Line
    Hardware
    A specially embedded system which is developed for this purpose
    Software
    The machine code loaded on the embedded system Memory
    User
    Other Machine, Supervisor
  3. Playing a game with a Computer
    Hardware
    Game console such as XBox, Playstation
    Software
    The game itself
    User
    The game player
US Navy 030423-N-6967M-090 A central computer system monitors the heart rates of each patient in the Intensive Care Unit (ICU) to ensure a quick
Hospital ICU monitoring system
public domain image


Mail sorting assembly line
Mail sorting assembly line
By Jason V [CC-BY-SA-2.0], via Wikimedia Commons

Sega-Game-Gear-WB
Game system
public domain image

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Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
Attribution: Dr. Paul Mullins, Slippery Rock University
These notes began life as the Wikiversity course Introduction to Computers.
The course draws extensively from and uses links to Wikipedia.
A large number of video links are provided to labrats.tv. (I hope you like cats. And food demos.)