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संगणकशास्‍त्रं

In its most general sense, computer science (CS or compsci) is the study of computation and information processing, both in hardware and in software. In practice, computer science includes a variety of topics relating to computers, which range from the abstract analysis of algorithms, formal grammars, etc. to more concrete subjects like programming languages, software, and computer hardware. As a scientific discipline, it differs significantly from mathematics, programming, software engineering, and computer engineering, although these fields are often confused.

The Church-Turing thesis states that all known kinds of general computing devices are essentially equivalent in what they can do, although they vary in time and space efficiency. This thesis is a fundamental principle of computer science. Most research in computer science has been related to von Neumann computerss or Turing machines (computers that do one small, deterministic task at a time). These models resemble most real computers in use today. Computer scientists also study other kinds of machines, some practical (like parallel machines) and some theoretical (like random, oracle, and quantum machines).

Computer scientists study what programs can and cannot do (see computability and artificial intelligence), how programs should efficiently perform specific tasks (see algorithms), how programs should store and retrieve specific kinds of information (see data structures and data bases), and how programs and people should communicate with each other (see human computer interaction and user interfaces).

Computer science has roots in electrical engineering, mathematics and linguistics. In the last third of the 20th century computer science has become recognized as a distinct discipline and has developed its own methods and terminology.

Table of contents

1 Related fields
2 Major fields of importance for computer science

2.1 Mathematical foundations
2.2 Theoretical computer science
2.3 Hardware
2.4 Computer systems organization
2.5 Software
2.6 Data and information systems
2.7 Computing methodologies
2.8 Computer applications
2.9 Computing milieux

3 History
4 Prominent pioneers in computer science
5 See also
6 External links

Information science is the study of data and information, including how to interpret, analyze, store, and retrieve it. Information science started as the foundation of scientific analysis of communication and databases.
Computer programming or software development is the act of writing program code.
Lexicography and specialized lexicography focus on the study of lexicographic reference works and include the study of electronic and Internet-based dictionaries.
Linguistics is the study of languages, converging with computer science in such areas as programming language design and natural language processing.
Software engineering emphasizes analysis, design, construction, and testing of useful software. Software engineering can include development methodologies (such as the waterfall model and extreme programming) and software project management.
Information systems (IS) is the application of computing to support the operations of an organization: operating, installing, and maintaining the computers, software, and data.
- Management information systems (MIS) is a subfield of information systems, that emphasizes financial and personnel management.
Mathematics shares many techniques and topics with computer science, but is more general. In some sense, CS is the mathematics of computing.
Logic is a formal system of reasoning, and studies principles that lay at the very basis of computing/reasoning machines, whether it be the hardware (digital logic) or software (verification, AI etc.) levels. The subfield of logic called computability logic provides a systematic answer to the fundamental questions about what and how can be computed.
Computer engineering is the analysis, design, and construction of computer hardware.
Information security is the analysis and implementation of information system security, including cryptography.

Major fields of importance for computer science

Mathematical foundations

Boolean algebra
Discrete mathematics
Graph theory
Information theory
Symbolic logic
Probability and Statistics

Theoretical computer science

Algorithmic information theory
Computability theory
Cryptography
Formal semantics
Theory of computation (or theoretical computer science)
- analysis of algorithms and problem complexity
- logics and meanings of programs
- Mathematical logic and Formal languages
Type theory

Hardware

(see also electrical engineering)

Control structures and Microprogramming
Arithmetic and Logic structures
Memory structures
input/output and Data communications
Logic Design
Integrated circuits
- VLSI design
Performance and reliability

Computer systems organization

(see also electrical engineering)

Computer architecture
Computer networks
- Distributed computing
Performance of systems
Computer system implementation

Software

Computer program and Computer programming
- Parallel Programming
- Program specification
- Program verification
Programming techniques
Software engineering
- Optimization
- Software metrics
- Configuration management and Software Configuration Management (SCM)
- Structured programming
- Object orientation
- Design patterns
Programming languages
Operating Systems
Compilers
- Lexical analysis
- Parsing

Data and information systems

Data structures
Data storage representations
Data encryption
Data compression
Coding and Information theory
Files
- File formats
Information systems
- Databases
- Information Storage and retrieval
- Information Interfaces and Presentation

Computing methodologies

Symbolic and Algebraic manipulation
Artificial intelligence
Computer graphics
Image processing and computer vision
Pattern recognition
- Speech recognition
Simulation and Modeling
Document and text processing
Digital signal processing

Computer applications

Administrative data processing
- Enterprise resource planning
- Customer relationship management
Mathematical software
- Numerical analysis
- Automated theorem proving
- Computer algebra systems
Physical science and Engineering
- Computational chemistry
- Computational physics
Life and medical sciences
- Bioinformatics
- Computational Biology
- Medical informatics
Social and behavioral sciences
Arts and Humanities
Computer-aided engineering
Robotics
Human-computer interaction
- Speech synthesis
- Usability engineering

Computing milieux

Computer industry
History of computing hardware
Computers and education
Computers and society
- Computer supported cooperative work
Legal aspects of computing
- Free software and Open Source
Management of computing and Information systems
Personal computing
Computer and information security

History

History of computing
Origins of computer terms
Early programming projects
Computer science departments
Timeline of algorithms

Prominent pioneers in computer science

Charles Babbage, Designed and built a prototype for a mechanical calculator; designed, but never built, the more powerful Analytical Engine.
John Backus Invention of FORTRAN (Formula Translation), the first practical high-level programming language and the Backus-Naur form for describing formal language syntax.
James W. Cooley and John W. Tukey The Fast Fourier Transform and its impact on scientific research.
Ole-Johan Dahl and Kristen Nygaard, inventors of the proto-object oriented language SIMULA.
Edsger Dijkstra for algorithms, Goto considered harmful, rigor, and pedagogy.
C.A.R Hoare for the development of the formal language Communicating Sequential Processes (CSP) and Quicksort.
Admiral Grace Murray Hopper, for doing pioneer work in the 1940s, one of the first to recognize the necessity for higher level programming languages, or what she termed automatic programming. She wrote the A-O compiler. Her ideas heavily influenced the COBOL language.
Kenneth Iverson Inventor of APL, for his contribution to interactive computing.
William Kahan for the IEEE floating-point standard. (Perhaps this reference should be moved to hardware engineering.)
Donald Knuth for The Art of Computer Programming series.
Ada Lovelace, contemporary of Charles Babbage, famous for her Sketch of the Analytical Engine, an analysis of Babbage's work; the namesake for the modern computer language, Ada.
John von Neumann for devising the von Neumann architecture upon which most modern computers are based.
Claude E. Shannon for information theory.
Alan Turing for computability theory, pioneering work in the field of Artificial Intelligence, and for the design of the Pilot ACE.
Maurice Wilkes for building the first practical stored program computer to be completed, and creditted with the ideas of several high-level programming language constructs.
James H. Wilkinson The technique of "backward error analysis" and advances in the field of matrix computations. Wilkinson was also a principal mover in the development of the Pilot ACE, the first British computer, in the late 1940s. (See more on Wilkinson in the MacTutor Biographies.)
Konrad Zuse Builder of a binary computer in the 1930s, for which he allegedly devised a theoretical high level programming language, Plankalkül.

See list of computer scientists for many more notables.