Difficulty: Introductory | Prerequisites: None
This topic sits right at the start of CS 101 and sets the stage for everything that follows. Before you write a single line of code or study an algorithm, it helps to understand what computer science actually is, where the discipline came from, and why there is still debate about whether it belongs with the sciences, with mathematics, or with engineering. If you have missed early lectures, start here.
Computer science is the study of computation and information, not simply the study of computers. The discipline has roots in mathematics and logic, draws on the work of figures like Turing, Godel, and von Neumann, and overlaps with fields ranging from engineering to linguistics. There is still active debate about whether CS is best understood as a science, a branch of mathematics, or a form of engineering.
Computer science
The study of computation, algorithms, information, and the principles underlying the design and use of computer systems. In simple terms, it is the discipline concerned with what can be computed, how efficiently, and by what means.
Datalogy
A term coined at the University of Copenhagen in 1969 by Peter Naur, used mainly in Scandinavia as a synonym for computer science. Think of it as the original Nordic name for the field.
Informatics
The term used across continental Europe (informatique in French, Informatik in German, informatica in Italian/Dutch, informatica in Spanish/Portuguese) for the discipline. In the US, "informatics" typically refers to applied computing within another domain (e.g. health informatics, bioinformatics).
Data science
Also proposed by Peter Naur as an alternative to "datalogy." Now refers to a multidisciplinary field covering data analysis, statistics, and databases. Think of it as the modern, broader cousin of Naur's original term.
Software engineering
The discipline focused on designing and building specific software systems to meet practical goals. Often distinguished from computer science, which studies the general principles of computation. In simple terms, CS asks "what is computable?" while software engineering asks "how do we build reliable software?"
Empirical science
A field that tests hypotheses through observation and experiment. Allen Newell and Herbert A. Simon argued in 1975 that computer science qualifies as one, because it studies the behaviour of computational artefacts through experimentation.
The first department to use the term "datalogy" was founded at the University of Copenhagen in 1969, with Peter Naur as its first professor.
In the early days, humorous job titles were proposed in Communications of the ACM: turingineer, turologist, flow-charts-man, applied epistemologist, comptologist, and hypologist.
Continental Europe adopted terms derived from "automatic information" rather than "computer science": informatique (French), Informatik (German), informatica (Italian, Dutch), informatica (Spanish, Portuguese), informatika (Slavic and Hungarian), pliroforiki (Greek).
In the UK, "informatics" is used (e.g. the School of Informatics at the University of Edinburgh). In the US, "informatics" typically means computing applied within another field.
A widely quoted remark, often attributed to Edsger Dijkstra: "Computer science is no more about computers than astronomy is about telescopes."
The point: CS is about computation as an abstract concept, not about the physical machines. The hardware is the instrument, not the subject.
CS intersects with cognitive science, linguistics, mathematics, physics, biology, earth science, statistics, philosophy, and logic.
Many consider CS to have a closer relationship with mathematics than with most natural sciences. Some commentators argue computing is, at its core, a mathematical discipline.
Foundational CS was heavily shaped by the work of mathematicians: Kurt Godel, Alan Turing, John von Neumann, Rozsa Peter, Stephen Kleene, and Alonzo Church.
There is ongoing exchange between CS and mathematics in areas such as mathematical logic, category theory, domain theory, and algebra.
David Parnas drew a distinction: CS studies the properties of computation in general; software engineering focuses on designing specific computing solutions to meet practical goals.
The two are complementary but distinct.
Whether a university department leans toward science or engineering often depends on whether it was founded with a mathematical emphasis or a technology emphasis.
Departments with a maths orientation tend to align with computational science; those with an engineering orientation bridge to industry but may not span all areas of inquiry.
Is computer science a science, a branch of mathematics, or a technology? This remains an open question.
Allen Newell and Herbert A. Simon argued in 1975 that CS is an empirical science, because it studies the behaviour of computational artefacts through observation and experiment.
The answer has practical implications: it shapes funding, departmental structure, and the kinds of research that get supported.
Students often think "computer science" means learning how to use computers or fix hardware. It does not. CS is about computation, algorithms, and information, not IT support.
Students often assume CS and software engineering are the same thing. They are related but distinct: CS studies general principles of computation, while software engineering is about building reliable systems to meet practical goals.
Students sometimes believe CS is purely a branch of mathematics. While CS has deep mathematical roots and ongoing ties to maths, it also has empirical and engineering dimensions. The classification remains genuinely debated.
Students often overlook the European terminology. If you see "informatics" or "informatique" on a paper or textbook, that is the same discipline as computer science, not a separate field.
⚠️ Know the Dijkstra quote and what it means: CS is about computation, not about the machines themselves.
⚠️ Be able to distinguish computer science from software engineering, using Parnas's framing: general principles versus practical system design.
⚠️ Know who Peter Naur was and what "datalogy" refers to.
⚠️ Be ready to name at least three foundational figures (Turing, Godel, von Neumann, Church, Kleene, Peter) and state their connection to CS.
⚠️ Understand the Newell and Simon argument: CS is an empirical science because it studies computational artefacts through experiment.
⚠️ Expect a question on why "informatics" and "computer science" refer to the same discipline in different regions.
True or false: Computer science is primarily the study of computer hardware. (False. CS studies computation and information, not the physical machines.)
Fill in the blank: The first department of "datalogy" was founded at the University of ______ in 1969. (Copenhagen)
True or false: "Informatics" and "computer science" refer to different disciplines. (False. They are different regional names for the same field.)
Fill in the blank: David Parnas argued that CS studies the properties of computation in general, while ______ focuses on designing systems to meet practical goals. (software engineering)
True or false: Allen Newell and Herbert A. Simon argued that CS is a branch of pure mathematics. (False. They argued it is an empirical science.)
Q: What did Edsger Dijkstra's famous remark about computer science mean?
A: That computer science is fundamentally about computation as an abstract concept, not about the physical machines (computers) used to carry it out, just as astronomy is about celestial bodies, not telescopes.
Q: Name three mathematicians whose work shaped early computer science, and briefly state why they matter.
A: Alan Turing (formalised the concept of computation with the Turing machine), Kurt Godel (proved fundamental limits on formal systems with his incompleteness theorems), and John von Neumann (contributed the stored-program architecture and foundational work in game theory and logic). Others: Alonzo Church (lambda calculus), Stephen Kleene (recursion theory), Rozsa Peter (recursive functions).
Q: How did David Parnas distinguish computer science from software engineering?
A: Parnas argued that computer science studies the general properties of computation, while software engineering focuses on designing specific computing solutions to achieve practical goals. The two are complementary but have different aims.
Q: Why is the term "informatics" used in Europe while "computer science" dominates in the US?
A: European terms (informatique, Informatik, informatica, etc.) derive from "automatic information," reflecting a tradition that frames the field around information processing. The US settled on "computer science." In the US, "informatics" usually refers to computing applied within another discipline, such as bioinformatics or health informatics.
Q: What was the Newell and Simon argument about the nature of computer science?
A: In 1975, Allen Newell and Herbert A. Simon argued that computer science is an empirical science. Their reasoning was that CS studies the behaviour of computational artefacts through observation and experiment, much as natural sciences study natural phenomena.
This material connects directly to the study of algorithms and data structures later in CS 101, because understanding what computation is comes before studying how to do it efficiently. The foundational figures mentioned here (Turing, Church, Godel) reappear when you study computability and formal languages. The CS-versus-engineering distinction becomes practical when you reach software design courses.
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