CS 101 › Lesson 1 of 8

What Is Computer Science?

Lesson 1 · OKSTEM College · Associate of Science in Computer Science

What Is Computer Science?

Computer science is the study of computation — how problems can be described, solved, and automated. It is not just programming. CS includes theory, mathematics, hardware, software, and the impact of computing on society.

Three Core Pillars

Computational Thinking

The fundamental skill CS teaches is computational thinking: breaking problems into steps (decomposition), finding patterns, abstracting away irrelevant details, and expressing solutions as algorithms.

Example: A recipe is an algorithm. It takes inputs (ingredients), performs steps in order, uses conditionals ("if dough is sticky, add flour"), and produces an output (bread).

Abstraction Layers

Computers are understood at multiple levels of abstraction, each hiding complexity from the layer above it:

LayerWhat You SeeWhat's Hidden
ApplicationWeb browser, gameOS calls, memory
Operating SystemFiles, processesHardware drivers
ArchitectureInstructions, registersCircuits
Digital LogicGates, flip-flopsTransistors
PhysicsTransistors, voltageQuantum effects

As a computer scientist you work at whichever layer the problem demands. This course tours all of them.

Lab — Decomposition Exercise

Knowledge Check

Computer science is primarily about

Which of these is an example of computational thinking?

The layer of abstraction that manages files and processes is the

An algorithm must be

Abstraction is useful because it

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