Computer Concepts: A Brief Overview

Simply expressed, a computer is an electronic machine (a system of components) capable of receiving, storing, and manipulating data and generating information. A modern-day computer system typifies what is known as the Von Neumann architecture that allows for a stored program concept consisting of devices used for input (e,g, keyboard & mouse), processing (the Central Processing Unit, CPU), primary/main memory (RAM/ROM), secondary/auxiliary memory (mass storage, e.g., hard disk, memory stick, DVD) and output (e.g., LCD screen, printer, speaker).

A computer system (CS) is a combination of major components: hardware, software, data and people. [In an organizational context, conceived as a computer information system (CIS) other elements such as policies and procedures also become included.]

• The physical equipment associated with a computer system is called hardware.
• A set of instructions that tells the hardware what to do is called software.
• The collection of facts processed into information by the computer is called data -- more on this later.
• The most important component of a computer system, however, is people who use the powerful tool to solve real-world problems.
• The computer can be a  tool for virtually anyone in all kinds of contexts -- business, art, housekeeping, education, and the list is seemingly endless.

Software or a computer program represents a problem-solving algorithm, a set of ordered or step-by-step instructions that the computer must perform to produce the desired results. When a computer implements these instructions, it executes the program.

Computer Language – although ultimately the only language a computer understands is machine language (binary instruction codes specifically designed for each processor platform), many different high-level languages have been developed to help us write/construct computer programs more conveniently.

Examples include BASIC, FORTRAN, COBOL, PASCAL, TURING, C, C++, JAVA, etc. that are, to varying degrees, more like natural languages (e.g. English) we use.

• Programs written in these high-level languages must be translated back to machine language for execution by the machine; a compiler is a program associated with each language that makes this possible.
• A computer programmer is a person who writes programs that we, the end-users can purchase or acquire and use for our specific purposes.

Data – raw facts, collected from different sources; cannot be the basis for meaningful conclusions on their own.

Data processing (DP) refers to the techniques of collecting, manipulating, and distributing data to achieve certain results. The objective of DP is to convert raw data into useful information, however, the term, information processing, is frequently used interchangeably with DP.

The process of creating useful information, i.e., defining relationships among data, requires knowledge that consists of

• the awareness and understanding of a set of information;
• the ways of making information useful to support a specific decision or task.

Knowledge is the basis of fact-selection/rejection relevant to specific information generation tasks.

Information -- material or data that has been organized and processed into meaningful form; can be used to educate; improve understanding. Useful information is typically characterized as being accessible, accurate, complete, economical, flexible, relevant, reliable, secure, simple, timely and verifiable.

• The information’s value is related directly to the degree to which it aids the makers of decisions or performers of tasks.

The Transfer-of-Information Cycle – the input-processing-output cycle by which a user communicates with a computer.

Major Strengths of Computers:

• SPEED -- can perform millions of calculations in one second
• ACCURACY -- the constancy of computer-generated results is referred to as accuracy Due to inherent reliability of electronic circuits passing the same type of current through the same electrical circuit will yield the same result; analogy -- turning on the light. This does not imply that such results are correct; garbage-in-garbage-out, the GIGO principle.
• MEMORY -- storage capacity measured by units such as: bit(one binary digit, 0/1), byte (a sequence of 8 bits), kilobyte (1024 Bytes), megabyte (1024 KB), gigabyte (1024 MB), terabyte (1024 GB), petabyte (1024 TB), exabyte (1024 PB).

Basic Computer Functions

• arithmetic calculations and logical operations (The arithmetic/logic unit -- the ALU -- is a major component of the CPU.)
• comparison -- test relationships between two values (e.g. are they equal? Which one is larger?, etc. also performed by the ALU)
• storage and retrieval of data to and from memory

Major Weaknesses of Computers:

• Computers do not possess independent intelligence; they cannot perform any task that a person/programmer has not predetermined.
• Computers are accurate (consistent) but are susceptible to producing incorrect results. Errors can result from input -- (GIGO); and from the physical world -- temperature, humidity, and electrical disturbances.

Types of Computers:

• General-purpose: a machine capable of performing various tasks according to the application program it has been given, e.g., PCs
• Special-purpose: a machine that has been designed and manufactured to perform a specific task. The instructions are hardwired, e.g., computers embedded in cars, watches, appliances, etc.

WHY IS THE STUDY OF COMPUTERS AND COMPUTER APPLICATIONS IMPORTANT?

It is important for everyone in a modern society to become aware of how computer use has affected, is affecting, and will affect society; and to become aware of the potential dangers and possible negative consequences of computer use; and to become informed citizens so that we can adapt to the changes more readily, can speak intelligently about computers and their use in society, and to make certain that they will be utilized effectively so as to benefit all of us. This is especially so for the intelligent, the intellectual or the educationally privileged members of society like you and your classmates.