Computer science

Computer science is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. Many diverse fields exist within the broader discipline of computer science; some emphasize the computation of specific results (such as graphics), while others (such as computational complexity theory) relate to properties of algorithms used in performing computations. Still others focus on the problems involved in implementing computations. For example, programming language theory studies approaches to describing a computation, while computer programming applies specific programming languages to craft a solution to some concrete computational problem.

History

The history of computer science predates the invention of the modern digital computer. Prior to the 1920s, the term computer referred to a human clerk that performed calculations. Early researchers in what came to be called computer science, such as Kurt Gödel, Alonzo Church, and Alan Turing, were interested in the question of computability: what things can be computed by a human clerk who simply follows a list of instructions with paper and pencil, for as long as necessary, and without ingenuity or insight. Part of the motivation for this work was the desire to develop computing machines that could automate the often tedious and error-prone work of a human computer.

During the 1940s, as newer and more powerful computing machines were developed, the term computer came to refer to the machines rather than their human predecessors. As it became clear that computers could be used for more than just mathematical calculations the field of computer science broadened to study computation in general.

Computer science education

Some universities teach computer science as a theoretical study of computation and algorithmic reasoning. These programs often feature the theory of computation, analysis of algorithms, formal methods, concurrency theory, databases, computer graphics and systems analysis, among others. They typically also teach computer programming, but treat it as a vessel for the support of other fields of computer science rather than a central focus of high-level study.

Other colleges and universities, as well as secondary schools and vocational programs that teach computer science, emphasize the practice of advanced computer programming rather than the theory of algorithms and computation in their computer science curricula. Such curricula tend to focus on those skills that are important to workers entering the software industry. The practical aspects of computer programming are often referred to as software engineering. However, there is a lot of disagreement over what the term "software engineering" actually means, and whether it is the same thing as programming.

Relationship with other fields

Despite its name, computer science rarely involves the study of computers themselves. In fact, the renowned computer scientist Edsger Dijkstra is often quoted as saying, "Computer science is no more about computers than astronomy is about telescopes." The design and deployment of computers and computer systems is generally considered the province of disciplines other than computer science. For example, the study of computer hardware is usually considered part of computer engineering, while the study of commercial computer systems and their deployment is often called information technology or information systems. However, there has been much cross-fertilization of ideas between the various computer-related disciplines. Computer science research has also often crossed into other disciplines, such as artificial intelligence, cognitive science, physics (see quantum computing), and linguistics.

The relationship between computer science and software engineering is a contentious issue, which is further muddied by disputes over what the term "software engineering" means, and what the definition of computer science is. Some people believe that software engineering is a subset of computer science. Others, taking a cue from the relationship between other engineering and science disciplines, believe that the principle focus of computer science is studying the properties of computation in general, while the principle focus of software engineering is the design of specific computations to achieve practical goals, making them different disciplines. This view is promulgated by (among others) David Parnas . Still others maintain that software cannot be engineered at all.

Fields of computer science

Mathematical foundations

Cryptography: algorithms for protecting private data, including encryption
Graph theory: Foundations for Data Storage structure and searching algorithms.
Mathematical logic
Type Theory: formal analysis of the types of data, and the use of these types to understand properties of programs, especially program safety

Theory of computation

Automata theory
Computability theory
Computational complexity theory: fundamental bounds (esp. time and storage space) on computations

Algorithms and data structures

Analysis of algorithms
Algorithms: formal processes used for computation, and the efficiency of these processes
Data structures: the organization and manipulation of data

Programming languages and compilers

Compiler construction: ways of translating computer programs, usually from higher level languages to lower level ones
Programming languages: formal languages for expressing algorithms and the properties of these languages

Databases

Data mining: study of algorithms for searching and processing information in documents and databases; closely related to information retrieval

Concurrent, parallel, and distributed systems

Concurrency: theory and practice of simultaneous and interacting computation
Parallel computing: theory and practice of computing using multiple computers and multiple processors in parallel

Computer architecture

Computer architecture: the design, organization, optimization and verification of a computer system at the gate level, mostly about CPUs and Memory subsystem
Networking: algorithms and protocols for reliably communicating data across long distances, often including error correction
Operating systems: systems for managing computer programs and data structures

Software engineering

Computer programming: the act of writing algorithms in a programming language
Formal methods: mathematical approaches for describing and reasoning about software designs
Software engineering: the principles and practice of designing, developing, and testing programs

Artificial intelligence

Artificial intelligence: the implementation and study of systems that exhibit (either behaviourally or seemingly) an autonomous intelligence or behaviour of their own, sometimes inspired by the characteristics of living beings. Computer science is closely tied with AI, as software and computers are primary tools for the development and progression of artificial intelligence.
Automated reasoning
Robotics: algorithms for controlling the behaviour of robots
Computer vision: algorithms for extracting three dimensional objects from a two dimensional picture

Computer graphics

Computer graphics: algorithms both for generating visual images synthetically and for integrating or altering visual and spatial information sampled from the real world
Image processing: Remote Sensing

Scientific computing

Bioinformatics

Careers

Graduates in Computer Science may pursue careers in (among others):

Computer programming	writing the software that runs on a computer
Software engineering	designing, managing, and writing large software systems
Systems analysis	solving computer problems and applying computer technology to meet the individual needs of an organization
Computer science	performing research, often in a specialized field of computer science
Database administration	designing and managing computer database systems and managing the security of those systems, a job often also done by specialists in information technology
Web development	design, development, and maintenance of World Wide Web sites, though web development is also frequently the domain of graphic designers and information technology specialists.