AskDefine | Define software

Dictionary Definition

software n : (computer science) written programs or procedures or rules and associated documentation pertaining to the operation of a computer system and that are stored in read/write memory; "the market for software is expected to expand" [syn: software system, software package, package] [ant: hardware]

User Contributed Dictionary

see Software

English

Pronunciation

  • US English /sAftwEr\`/
  • [ˈsɔft.wɛɻ]

Etymology

soft + ware

Noun

  1. Encoded computer instructions, usually modifiable (unless stored in some form of unalterable memory such as ROM). Compare hardware.
    • 1958: The "software" comprising the carefully planned interpretive routines, compilers, and other aspects of automative programming are at least as important to the modern electronic calculator as its "hardware" of tubes, transistors, wires, tapes and the like. — The Teaching of Concrete Mathematics, John W. Tukey, in The American Mathematical Monthly, vol. 65, no. 1 (Jan. 1958), pp 1-9.
    • 1953 As originally conceived, the word "software" was merely an obvious way to distinguish a program from the computer itself. A program comprised sequences of changeable instructions each having the power to command the behavior of the permanently crafted machinery, the "hardware." Softword: Provenance for the Word ‘Software’ by Paul Niquette ISBN 1-58922-233-http://niquette.com/books/softword/part0.htm
encoded computer instructions

See also

Extensive Definition

Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system. The term includes application software such as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, and middleware which controls and co-ordinates distributed systems.
"Software" is sometimes used in a broader context to mean anything which is not hardware but which is used with hardware, such as film, tapes and records.

Relationship to computer hardware

Computer software is so called to distinguish it from computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. In computers, software is loaded into RAM and executed in the central processing unit. At the lowest level, software consists of a machine language specific to an individual processor. A machine language consists of groups of binary values signifying processor instructions which change the state of the computer from its preceding state. Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. High-level languages are compiled or interpreted into machine language object code. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler.
The term "software" was first used in this sense by John W. Tukey in 1958. In computer science and software engineering, computer software is all computer programs. The theory that is the basis for most modern software was first proposed by Alan Turing in his 1935 essay Computable numbers with an application to the Entscheidungsproblem.

Types

Practical computer systems divide software systems into three major classes: system software, programming software and application software, although the distinction is arbitrary, and often blurred.

Program and library

A program may not be sufficiently complete for execution by a computer. In particular, it may require additional software from a software library in order to be complete. Such a library may include software components used by stand-alone programs, but which cannot work on their own. Thus, programs may include standard routines that are common to many programs, extracted from these libraries. Libraries may also include 'stand-alone' programs which are activated by some computer event and/or perform some function (e.g., of computer 'housekeeping') but do not return data to their calling program. Libraries may be called by one to many other programs; programs may call zero to many other programs.

Three layers

see also Software architecture Users often see things differently than programmers. People who use modern general purpose computers (as opposed to embedded systems, analog computers, supercomputers, etc.) usually see three layers of software performing a variety of tasks: platform, application, and user software.

Creation

Operation

Computer software has to be "loaded" into the computer's storage (such as a hard drive, memory, or RAM). Once the software has loaded, the computer is able to execute the software. This involves passing instructions from the application software, through the system software, to the hardware which ultimately receives the instruction as machine code. Each instruction causes the computer to carry out an operation -- moving data, carrying out a computation, or altering the control flow of instructions.
Data movement is typically from one place in memory to another. Sometimes it involves moving data between memory and registers which enable high-speed data access in the CPU. Moving data, especially large amounts of it, can be costly. So, this is sometimes avoided by using "pointers" to data instead. Computations include simple operations such as incrementing the value of a variable data element. More complex computations may involve many operations and data elements together.
Instructions may be performed sequentially, conditionally, or iteratively. Sequential instructions are those operations that are performed one after another. Conditional instructions are performed such that different sets of instructions execute depending on the value(s) of some data. In some languages this is known as an "if" statement. Iterative instructions are performed repetitively and may depend on some data value. This is sometimes called a "loop." Often, one instruction may "call" another set of instructions that are defined in some other program or module. When more than one computer processor is used, instructions may be executed simultaneously.
A simple example of the way software operates is what happens when a user selects an entry such as "Copy" from a menu. In this case, a conditional instruction is executed to copy text from data in a 'document' area residing in memory, perhaps to an intermediate storage area known as a 'clipboard' data area. If a different menu entry such as "Paste" is chosen, the software may execute the instructions to copy the text from the clipboard data area to a specific location in the same or another document in memory.
Depending on the application, even the example above could become complicated. The field of software engineering endeavors to manage the complexity of how software operates. This is especially true for software that operates in the context of a large or powerful computer system.
Currently, almost the only limitations on the use of computer software in applications is the ingenuity of the designer/programmer. Consequently, large areas of activities (such as playing grand master level chess) formerly assumed to be incapable of software simulation are now routinely programmed. The only area that has so far proved reasonably secure from software simulation is the realm of human art— especially, pleasing music and literature.
Kinds of software by operation: computer program as executable, source code or script, configuration.

Quality and reliability

Software reliability considers the errors, faults, and failures related to the creation and operation of software.

License

Software license gives the user the right to use the software in the licensed environment, some software comes with the license when purchased off the shelf, or an OEM license when bundled with hardware. Other software comes with a free software licence, granting the recipient the rights to modify and redistribute the software. Software can also be in the form of freeware or shareware. See also License Management.

Patents

The issue of software patents is controversial. Some believe that they hinder software development, while others argue that software patents provide an important incentive to spur software innovation. See software patent debate.

Ethics and rights for software users

Being a new part of society, the idea of what rights users of software should have is not very developed. Some, such as the free software community, believe that software users should be free to modify and redistribute the software they use. They argue that these rights are necessary so that each individual can control their computer, and so that everyone can cooperate, if they choose, to work together as a community and control the direction that software progresses in. Others believe that software authors should have the power to say what rights the user will get.

Software companies

Examples of large software companies are: Microsoft, IBM, Oracle, SAP and HP.

References

External links

software in Afrikaans: Sagteware
software in Arabic: برمجيات
software in Asturian: Programa d'ordenador
software in Min Nan: Nńg-thé
software in Bosnian: Softver
software in Breton: Meziant
software in Bulgarian: Програмно осигуряване
software in Catalan: Programari
software in Czech: Software
software in Danish: Computerprogram
software in German: Software
software in Estonian: Tarkvara
software in Spanish: Software
software in Esperanto: Programaro
software in Basque: Software
software in Persian: نرم‌افزار
software in French: Logiciel
software in Galician: Programa informático
software in Gujarati: સૉફ્ટવેર
software in Classical Chinese: 軟體
software in Korean: 컴퓨터 소프트웨어
software in Hindi: सॉफ्टवेयर
software in Croatian: Programska podrška
software in Indonesian: Perangkat lunak
software in Interlingua (International Auxiliary Language Association): Software
software in Inuktitut: ᐊᕿᑦᑐᖅ ᖃᕆᑕᐅᔭᐅᑉ ᑎᑎᕋᕐᕕᖓ/aqittuq qaritaujaup titirarvinga
software in Icelandic: Hugbúnaður
software in Italian: Software
software in Hebrew: תוכנה
software in Kurdish: Nermalav
software in Latin: Res informatica
software in Latvian: Programmatūra
software in Luxembourgish: Software
software in Lithuanian: Programinė įranga
software in Hungarian: Szoftver
software in Malayalam: സോഫ്‌റ്റ്‌വെയര്‍
software in Malay (macrolanguage): Perisian komputer
software in Dutch: Software
software in Newari: सफ्टवेर
software in Japanese: ソフトウェア
software in Norwegian: Dataprogram
software in Norwegian Nynorsk: Programvare
software in Low German: Software
software in Polish: Oprogramowanie
software in Portuguese: Software
software in Romanian: Software
software in Russian: Программное обеспечение
software in Albanian: Software
software in Sicilian: Software
software in Simple English: Software
software in Slovak: Softvér
software in Slovenian: Programska oprema
software in Finnish: Tietokoneohjelma
software in Swedish: Programvara
software in Tagalog: Software
software in Tatar: Sanaq programı
software in Thai: ซอฟต์แวร์
software in Vietnamese: Phần mềm
software in Turkish: Yazılım
software in Ukrainian: Програмне забезпечення
software in Venetian: Software
software in Yiddish: ווייכווארג
software in Chinese: 软件
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1