Computer science

simple:Computer science zh-cn: %E8%AE%A1%E7%AE%97%E6%9C%BA%E7%A7%91%E5%AD%A6 In its most general sense, computer science (CS) 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 to more concrete subjects like programming languages, software, and computer hardware. As a scientific discipline, it is a very different activity from computer programming and computer engineering, although the three are often confused.

Computer science is no more about computers than astronomy is about telescopes

- Edsger Dijkstra

Computer science is not as old as physics; it lags by a couple of hundred years. However, this does not mean that there is significantly less on the computer scientist's plate than on the physicist's: younger it may be, but it has had a far more intense upbringing!

- Richard Feynman

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 sometimes treated as the 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), because they resemble most real computers in use today. Computer scientists also study other kinds of machines, some practical (like parallel and quantum machines) and some theoretical (like random and oracle machines).

Computer science studies what programs can and cannot do (computability and artificial intelligence), how programs should efficiently perform specific tasks (algorithms), how programs should store and retrieve specific kinds of information (data structures), and how programs and people should communicate with each other (user interfaces and programming languages).

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.

The first computer science department in the United States was founded at Purdue University in 1962. The University of Cambridge in England, among others, was teaching the subject prior to this (Cambridge claims to have the world's oldest taught qualification in computing). However, at the time computer science was still seen as a branch of mathematics, so whether those universities had separate computer science departments is arguable. Most universities today have specific departments devoted to the subject.

The highest honor in computer science is the Turing Award.

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

Related fields

Computer science is closely related to several other fields. These fields overlap considerably, though important differences exist

• 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.
• Software engineering emphasizes analysis, design, and construction of useful software using contemporary tools and practices.
• Information systems is the application of computing to support the operations of an organization: operating, installing, and maintaining the computers, software, and data. Management information systems is a key subfield that emphasizes financial and personnel management.

• Computer engineering is about the analysis, design, and construction of computer hardware.
• Information security is about the analysis and implementation of information system security (cryptography is included).

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
  • Structured programming
  • Object orientation
  • Design patterns
  • Free software and Open Source
• 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
• Mathematical software
  • Numerical analysis
  • Automated theorem proving
  • Computer algebra
• 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

• The computer industry
• History of computing hardware
• Computers and education
• Computers and society
  • Computer supported cooperative work
• Legal aspects of computing
• 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 but never completed plans for several mechanical calculators and one mechanical programmable computer.
• John Backus Invention of FORTRAN, 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.
• 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 The Art of Computer Programming series.
• Ada Lovelace famous as the world's first ever computer programmer.
• 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, and designed Pilot ACE,
• 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 the first binary computer in the 1930s, for which he devised a programming language considered ahead of its time.

See list of computer scientists for many more notables.

See also

• Computing
• History of computing
• History of computing hardware
• Turing Award (ACM)
• IEEE John von Neumann Medal
• Computer jargon
• Computer slang
• Computer science basic topics
• Computing analogies
• Internet
• Multimedia
• Data acquisition
• Benchmark
• Sensor network
• Online computations and algorithms,
• Computer numbering formats