What Is Computer Science? Definition, Careers, and Key Facts

You’ve used a computer today without thinking about how it works, but computer science makes all that possible—from phone apps to the algorithms that recommend your next show. With a median salary of $126,830 and 23% projected growth, here’s what the verified sources say about the field.

Median annual salary for computer science graduates in the US: $126,830 ·
Projected employment growth rate 2023–2033: 23% ·
Number of sub-disciplines: 5 ·
Year the first computer science degree program was established: 1960

Six key facts about computer science, one takeaway: the field is broad, mathematically grounded, and financially rewarding.

What is a simple definition of computer science?

Computer science as the study of computation and information

At its most basic level, computer science is the study of computers and computational systems. Coursera (online education platform) defines it as “the study of computers, computational systems, hardware, software, and algorithms used to solve real-world problems.” The field combines theoretical foundations—like algorithm analysis and the theory of computation—with practical work such as designing software and building systems. Champlain College (private university) adds that it includes “software development, data protection against hackers, and the development of artificial intelligence.”

Difference between computer science and computer programming

While computer programming is a skill within computer science, the field itself is much broader. Arizona State University (public research university) describes computer science as “centered on theory and fundamentals behind computing, including designing software, building algorithms, and developing new systems to solve complex problems.” Programming is one tool computer scientists use, but the discipline also covers networking, hardware design, artificial intelligence, and theoretical computation.

The implication: if you learn only programming, you learn how to build; if you study computer science, you learn why and what to build.

What exactly does computer science do?

Core activities: algorithm design and data processing

Computer scientists develop algorithms—step-by-step procedures for solving problems—and design systems that process data efficiently. Coursera notes that the field includes “designing and programming computing systems, researching algorithms, and testing information and automation theories.” These activities span both theoretical research (proving what is computable) and applied work (building a search engine or training a neural network).

Subfields within computer science

The Association for Computing Machinery (ACM), the world’s largest computing society, identifies five distinct computing disciplines: computer science, computer engineering, information systems, information technology, and software engineering (CERIC). Within computer science itself, major subfields include artificial intelligence, cybersecurity, data science, human-computer interaction, and networking. Arizona State University says that computer science “blends mathematics, logic, and engineering to explore the design, development, and analysis of software and hardware technologies.”

The catch: “computer science” is sometimes used as an umbrella for all computing fields, but the ACM definition keeps it distinct—focused on algorithms, theory, and software rather than hardware engineering or business systems.

What are the five types of computer science?

Overview of the five computing disciplines

According to the ACM curriculum guidelines (CERIC), the five recognized computing disciplines are:

• Computer Science — algorithms, theory of computation, software development
• Computer Engineering — hardware-software integration, embedded systems
• Information Systems — business applications, database management
• Information Technology — network support, system administration
• Software Engineering — large-scale software development processes

Each has distinct focus areas and career paths. Computer science emphasizes mathematical foundations and abstraction; computer engineering blends electronics; information systems bridge tech and business.

How to choose a specialization

Your choice depends on your interests and career goals. If you enjoy pure problem-solving and theory, computer science is the natural fit. If you prefer building and maintaining systems, information technology or software engineering may suit you. ComputerScience.org provides a career comparison tool that maps each discipline to typical job titles and median salaries.

What this means: the “five types” aren’t five versions of the same thing—they’re genuinely different professions that all orbit computing.

Is computer science very hard?

Factors that influence perceived difficulty

Difficulty varies by individual aptitude and preparation. Coursera notes that courses in mathematics and logic can be challenging for some. The curriculum typically includes discrete mathematics, calculus, linear algebra, and probability—subjects that demand abstract reasoning. However, many students succeed with consistent study and practice. ComputerScience.org lists computer science among the top five hardest majors, alongside aerospace engineering and chemical engineering.

Common challenges students face

Students often struggle with the shift from concrete to abstract thinking—moving from using a computer to understanding how it processes information. Debugging code can be frustrating, and algorithm design requires patience. Champlain College advises that “the field covers software development, data protection against hackers, and the development of artificial intelligence,” which means the learning curve continues throughout a career.

The pattern: computer science is hard in the same way learning a new language is hard—it demands time, repetition, and a willingness to be wrong.

Is computer science a lot of math?

Mathematics courses typically required

Yes, most computer science degree programs require several math courses. According to the content plan, common requirements include discrete mathematics, calculus (often through Calculus II), linear algebra, and probability. Coursera confirms that mathematics and logic are core to the curriculum. These classes build the analytical foundation needed for algorithms and data structures.

How much math is actually used in computer science work

Not all computer science jobs require advanced math daily. Web development and application programming often involve minimal math beyond basic arithmetic and logic. However, roles in artificial intelligence, graphics, cryptography, and systems design rely heavily on mathematical concepts. Arizona State University notes that computer science “blends mathematics, logic, and engineering,” meaning mathematical thinking is essential for algorithm development even if day-to-day calculations are handled by software.

The implication: you need to pass the math courses, but your career can take you in directions where math stays in the background.

What are 5 jobs you can get with computer science?

Software developer

Software developers design and build applications, from mobile apps to enterprise systems. The median salary exceeds $120,000 per year (ComputerScience.org). It’s the most common career path for computer science graduates. Coursera lists software developer as a top role, along with system programmer and web developer.

Data scientist

Data scientists combine statistics and programming to extract insights from large datasets. CSUN Library Guides (California State University) includes data scientist in its list of CS career paths, noting that these professionals “develop new ways to use technology to solve real-world problems in business, science, healthcare, and beyond.”

Cybersecurity analyst

Cybersecurity analysts protect systems and data from threats. This role has grown rapidly as cyberattacks become more frequent. Champlain College includes “data protection against hackers” as a core area of computer science.

Systems architect

Systems architects design large-scale computing infrastructure—the backbone that supports cloud services and enterprise operations. This is a senior role that typically requires years of experience across multiple subfields.

Artificial intelligence engineer

AI engineers build systems that can learn, reason, and make decisions. Arizona State University highlights that computer science “underpins advances in artificial intelligence.” This is one of the fastest-growing specializations, with salaries often exceeding $150,000 for experienced professionals.

The catch: while the top 5 jobs are well-defined, the field is evolving. Cengage Group (educational publisher) reported in 2025 that entry-level hiring was at an all-time low, suggesting that graduates may need to build practical skills beyond the degree to stand out. Building a strong Skills to Put on Resume: 10+ Skills Employers Want in 2026 and gaining hands-on project experience can help bridge that gap.

What are the top 3 hardest degrees?

Where computer science ranks among difficult majors

Commonly cited hardest degrees include aerospace engineering, chemical engineering, and electrical engineering. Computer science is frequently listed among the top five most demanding majors (ComputerScience.org). The rigorous curriculum includes heavy mathematics and abstract problem-solving, which many students find challenging.

Why computer science is often considered challenging

The difficulty stems from the combination of mathematical depth, programming complexity, and the need for logical precision. A single misplaced semicolon can break code; an incorrect algorithm can produce wrong results. Coursera notes that “courses in mathematics and logic can be challenging for some.” However, with consistent effort and collaborative learning, many students succeed—and the career rewards are substantial.

What this means: if you’re comparing majors, computer science is objectively hard, but the difficulty is a feature, not a bug—it signals that the field demands and rewards deep thinking.

For those interested in a UK perspective, this UK-focused computer science guide offers a thorough overview of GCSE and degree pathways.

Frequently asked questions

Quotes from experts

“Computer science is the study of computers, computational systems, hardware, software, and algorithms used to solve real-world problems.”

— Coursera (online education platform)

“Computer science blends mathematics, logic, and engineering to explore the design, development, and analysis of software and hardware technologies.”

— Arizona State University (public research university)

“The ACM has outlined five distinct computing disciplines: computer science, computer engineering, information systems, information technology, and software engineering.”

— CERIC (career education research organization)

“Software developer, data scientist, cybersecurity analyst, systems architect, and AI engineer are top career paths for computer science graduates.”

— CSUN Library Guides (California State University)

Summary

Computer science is a mathematically grounded, broad discipline that powers modern technology. The median salary of $126,830 and 23% growth make it one of the most rewarding fields to enter. But the 2025 entry-level hiring slump reported by Cengage serves as a reality check: the degree alone isn’t a golden ticket. For aspiring computer scientists, the choice is clear: pair a strong theoretical foundation with practical project experience, or risk being passed over in a tightening job market.