Program

Program may refer to any of the following:

1. As a verb, program or programming is a term used to describe the process of a programmer developing a software program by programming.

2. As a noun, an application, application software, or program is software on the computer that performs a specific function or task. For example, Microsoft Word is a word processing application that allows users to create and write documents, and a browser, such as the one you are using to view this page, is an application.

Apps vs. Programs

When Apple introduced the iPhone, they popularized the term "App," but an app (application) and program are the same thing. Today, most people think of an "app" as an application on an Apple computer, smartphone, or tablet and a program as something that runs on a computer (e.g., a Windows computer).

Tip

With all the different ways companies and people use these terms, it is best to think of an application, app, and program as the same thing. See our app page for further information on mobile apps.

Programs vs. Scripts

When a program is created, it is compiled into a language that the computer can understand. Once compiled, the program does not need any other programs to run as long it as the computer has the required operating system and platform. A script is not compiled and needs an interpreter to translate the script into something the computer understands. Without an interpreter, the script cannot run on the computer, but once installed a script can run on any platform without needing to be re-written. See our script term for further information and the pros and cons of scripts.

What type of files are program files?

A program file must be an executable file and for software programs running Microsoft Windows end with a file extension of .EXE, .COM, or .PIF. Executing these files runs the program and allows it to be used on the computer. On an Apple Macintosh computer, a program ends with .APP.

Examples of computer programs

There are millions of different programs available for computers, phones, and other devices today. Below are a few examples and the related program category.

Tip

If you visit the program category page, you can see other examples of programs of that category.

Program	Program Category
Adobe Acrobat	PDF reader
Adobe Dreamweaver	HTML editor
Adobe Photoshop	Photo editor
Audacity	Audio software
Comm Central	Fax/Voice/Phone
FileZilla	FTP
Google Chrome	Internet Browser
Hyper Terminal	Terminal program
Microsoft Excel	Spreadsheet
Microsoft PowerPoint	Presentation
Microsoft Word	Word processor
Mozilla Thunderbird	E-mail client
Norton Anti-Virus	Antivirus
C++	Programming language
Skype	Chat and VoIP

· See our software page for information on software that is considered a program and software that is a different category.

What is the purpose of a program?

Without application software (programs) your computer would be able to operate with the operating system (system software) but would not be capable of doing anything else. A program gives the computer and user the ability to perform specific tasks. For example, to browse the Interneton a computer, you would install a browser, which is a program that instructs the computer how to visit, display, and navigate a web page. Without a browser program, the computer would not be able to browse the Internet.

What are the basic functions of a program?

The functions of a program vary depending on the type of program. For example, the function of a browser program is to browse the Internet. The function of a word processor is to create, view, and edit documents. A program is usually designed to perform a specific task (function), and only that task. In other words, a word processor program may be able to create a document, but it cannot be used to browse the Internet.

Tip

See our program examples for a list of different types of programs and program categories.

Note

Today, with cloud computing and online services it may be confusing to know how to define a service such as Google Docs. Google Docs is a word processor, but it is a word processor capable of running through the browser and therefore is considered a web-based application and not a program.

Are games programs?

Yes, games are programs, but may be labeled as "games" and not "programs," to distinguish them as designed for leisure rather than productivity. As a category of programs, games have subcategories of their own, such as FPS, MMO, and RPG. For example, Quake is an "FPS game."

Is Microsoft Windows a program?

No. All versions of Microsoft Windows are considered an operating system and not a program.

What was the first program?

The first software program that was held in electronic memory was written by Tom Kilburn. The program calculated the highest factor of the integer 2¹⁸ = 262,144, and was successfully executed on June 21, 1948, at the University of Manchester, England. The computer was called the SSEM (Small Scale Experimental Machine), otherwise known as the "Manchester Baby.". This event is widely celebrated as the birth of software.

Computer Science Classification Of Software

The following diagram shows the way we classify software.

System Software

We use the term System Software for software which is primarily used to operate the hardware.

Operating Systems

The operating system is the software that allows you to operate the hardware. The programs that we want to execute, the applications that we want to use all require a platform on which to execute. That platform is provided by the operating system.

One role of the operating system is to provide a virtual machine. This refers to the way that, by clicking on icons and menus, or by typing in commands at a prompt, we get to interact with the computer hardware without having to understand its complexity. By hiding the true complexity of the system from the user, the operating system makes it easier for ordinary people to make computers perform useful tasks.

Utility Programs

Some utility programs are bundled in with operating system software these days. Others you buy or source in some other way.

Utility programs tend to perform specific tasks related to the management of hardware. Examples of utility programs include compression programs, formatters, defragmenters and other disk management tools.

Library Programs

Library programs are compiled libraries of commonly-used routines. On a Windows system they usually carry the file extension dll and are often referred to as run-time libraries. The libraries are run-time because they are called upon by running programs when they are needed. When you program using a run-time library, you typically add a reference to it either in your code or through the IDE in which you are programming.

Some library programs are provided within operating systems like Windows or along with development tools like Visual Studio. For example, it is possible to download and use a library of routines that can be used with Windows Media Player. This includes things like making playlists, functions and procedures for accessing and manipulating the music library (which is a binary file) and playback routines.

Using library programs saves time when programming. It also allows the programmer to interact with proprietary software without having access to its source code.

Language Translators

Whatever language or type of language we use to write our programs, they need to be in machine code in order to be executed by the computer. There are 3 main categories of translator used,

Assembler

An assembler is a program that translates the mnemonic codes used in assembly language into the bit patterns that represent machine operations. Assembly language has a one-to-one equivalence with machine code, each assembly statement can be converted into a single machine operation.

Compiler

A compiler turns the source code that you write in a high-level language into object code (machine code) that can be executed by the computer.

The compiler is a more complex beast than the assembler. It may require several machine operations to represent a single high-level language statement. As a result, compiling may well be a lengthy process with very large programs.

Interpreter

Interpreters translate the source code at run-time. The interpreter translates statements one-at-a-time as the program is executed.

Interpreters are often used to execute high-level language programs whilst they are being developed since this can be quicker than compiling the entire program. The program would be compiled when it is complete and ready to be released.

Interpreters are also used with high-level scripting languages like PHP, Javascript and many more. These instructions are not compiled and have to be interpreted either by the browser (in the case of Javascript) or by interpreters on the server (in the case of PHP).

Some programming languages make use of both compilers and interpreters. If you were to write a Java program in a text editor, when you came to compile it with the Java compiler, you would actually be creating something called bytecode. Bytecode can be thought of as an intermediate stage between source code and object code. When a computer executes a Java program, library programs on that machine interpret the bytecode. This allows Java to be platform-independent - a user needs the correct run-time libraries for Java on their machine in order to execute the programs.

Application Software

Application software tends be used for the tasks that have some relationship to the world outside of the computer. For example, you might use a word processor to write a letter or an essay. Although you use the computer to perform the task, the task itself might reasonably be considered to be a non-computer task.

General-Purpose Software

Software is general-purpose if it can be used for lots of different tasks. You can use a word processor to write letters, memos, essays, instructions, notes, faxes, invoices and lots more.

These days we tend to use integrate suites of office software where a range of general-purpose software is provided, usually with the facility to combine elements from each application in a single file.

Special-Purpose Software

This software performs a single specific task. This task might be complex like payroll calculation, stock control etc. but will be based on a single task.

As with many abstract concepts, you can stretch these definitions until they blur a little. These days, web browsers can contain a lot of features. They are still primarily focused on a single task, rendering web pages and so the web browser is special-purpose. Being able to access an application using a browser does not change the main purpose of the browser software itself.

Bespoke Software

Bespoke software is written for a single client. Large organisations have a need for well-developed applications suited to their specific needs. Such software is often expensive to develop since the development costs are not shared among a large number of people purchasing the software.

Generations Of Programming Language

First Generation Languages

Here we are talking about machine code. This is the only form of code that can be executed by the computer directly.

Second Generation Languages

Assembly language was developed to make it easier for programmers to write instructions than it would be using machine code. Mnemonics are used instead of bit patterns (which are harder to remember).

First and second generation languages are low level and machine-oriented. This refers to the way that they are based on the machine operations that are available for a given processor.

Third Generation Languages

Third generation languages are high level, platform-independent and problem oriented. When source code is compiled, there is a one-to-many equivalence of high level language statements to machine code statements. Third generation programs can be run on any platform for which an appropriate compiler or interpreter exists.

High level languages are developed to help solve particular types of problem. The FORTRAN language was designed with Mathematics, Science and Engineering in mind, it contains lots of scientific functions that the average programmer may not need. The COBOL language was developed with business logic in mind, PHP was developed for server-side scripting and so on.

All of the languages in the first 3 generations are called imperative languages because the program's statements are executed in the order specified by the programmer.

Fourth Generation Languages

Fourth generation languages are declarative. This means that the programmer will write facts or rules rather than statements. The interpreter for the language produces the result using whichever standard algorithms it has been given for doing so.

SQL and Prolog are both examples of declarative languages. Both are described in the programming section of this site and are relatively easy to try out. A quick half-hour blast at each would give you a feel for how they work and help you to understand how they differ from the other types of language.

GPS

Short for Global Positioning System, GPS is a network of satellites that helps users determine a location on Earth. The thought of GPS was conceived after the launch of Sputnik in 1957. In 1964, the TRANSIT system became operational on U.S. Polaris submarines and allowed for accurate positioning updates. Later this became available for commercial use in 1967. The picture shows an example of the GARMIN nuvi 350, a GPS used to find locations while driving.

On September 1, 1983, Soviet jets shot down a civilian Korean Airlines Flight 007 flying from New York to Seoul and kill all 269 passengers and crew. As a result of this mistake, President Ronald Regan orders the U.S. military to make GPS available for civilian use.

Today, with the right equipment or software, anyone can establish a connection to these satellites to establish his or her location within 50 to 100 feet.

Speaker

A speaker may refer to any of the following:

1.  A speaker is a term used to describe the user who is giving vocal commands to a software program.

2.   A computer speaker is an output hardware device that connects to a computer to generate sound. The signal used to produce the sound that comes from a computer speaker is created by the computer's sound card. The picture shows the Harman Kardon Soundsticks III 2.1 Channel Multimedia Speaker System.

How does it work?

Speakers are made up of a cone, an iron coil, a magnet, and housing (case). When the speaker receives electrical input from a device, it sends the current through the causing it to move back and forth. This motion then vibrates the outer cone, generating sound waves picked up by our ears.

Evolution of the computer speaker

When computers were initially released, they had on-board speakers built into the chassis that generated a series of different tones and beeps. The first internal computer speaker was invented by IBM in 1981 and produced basic, low quality sound.

As technology progressed, on board speakers moved to being built into the computer monitor and acquired the ability to produce voices, music, and other sound effects. The speakers were usually located on the bottom-left and bottom-right on the front of the monitor, but sometimes they were built into the left and right side of the monitor.

When computer gaming, digital music, and other media became popular, manufacturers began to make external speakers that produced higher quality sounds and improved bass. The first external computer speaker was invented by Abinawan Puracchidas in 1991 and are still the dominant type of speaker for computers.

Rating a speaker

Speakers are rated in frequency response, total harmonic distortion, and watts.

·   The Frequency response is the rate of measurement of the highs and lows of the sounds the speaker produces.

·   THD (total harmonic distortion) is the amount of distortion created by amplifying the signal.

·   The Watts is the amount of amplification available for the speakers.

Why do we need computer speakers?

External speakers are connected to a computer or another device to give the sound more amplification (make it louder), add more bass with a subwoofer, or create surround sound. If you have a laptop, smartphone, or another device with built-in speakers, you do not need external speakers unless you need louder sounds, more bass, or surround sound.

TV

Short for Television a TV or Telly is an electronics device that receives a visual and audio signal and plays it for the viewer. There is a debate over who is credited as being the inventor of the TV. The two candidates are Vladimir Zworykin a Russian-born American who worked for Westinghouse, and Philo Taylor Farnsworth, a boy in Beaver City, Utah. Vladimir held the patent for the TV, but it was Farnsworth who was the first person to successfully transmit a TV signal on September 7, 1927. The picture on the right shows the Panasonic TH-58PZ750U, a good example of a television.