This CS101 study guide reviews common introductory computer science concepts. Course material and assessments can change, so students should use their current Virtual University lectures and official course resources as the primary source for exam preparation.

Data and Storage

  • Bit: A binary digit represented by 0 or 1.
  • Byte: A group of eight bits.
  • RAM: Random-access memory used for data and instructions that a computer is actively working with.
  • SSD: Solid-state drive, a storage device that uses flash memory.
  • CD, DVD and Blu-ray: Optical-disc technologies with different capacities and formats.

Encoding and Compression

Computers represent information using binary patterns. Character-encoding standards such as ASCII and Unicode map characters to numeric values. Unicode supports a much larger range of writing systems and symbols than ASCII.

Compression reduces the amount of data required to represent information. Lossless compression allows the original data to be reconstructed exactly, while lossy compression accepts some information loss to achieve greater reduction.

Computer Hardware

Hardware means the physical components of a computer system. The processor executes instructions, main memory stores active data and instructions, and storage devices retain information for longer periods.

A bus provides communication paths between computer components. Pipelining is a processor technique that overlaps stages of instruction processing to improve throughput.

Networks and the Internet

  • LAN: Local Area Network.
  • WAN: Wide Area Network.
  • DNS: Domain Name System, which helps translate domain names into network addresses.
  • URL: Uniform Resource Locator.
  • WWW: World Wide Web.
  • VoIP: Voice over Internet Protocol.

Cybersecurity Basics

Malware is a broad term covering malicious software such as viruses, worms, Trojans and spyware. A denial-of-service attack attempts to make a service unavailable by overwhelming or disrupting it.

Modern secure web connections normally use TLS. SSL is its older predecessor, although the expression “SSL” is still sometimes used informally when referring to website certificates.

Algorithms and Programming

An algorithm is a defined sequence of steps for solving a problem. Pseudocode is one way to express an algorithm without depending on the exact syntax of a programming language.

Important introductory concepts include variables, conditions, loops, functions, recursion, searching and sorting. A recursive solution normally requires a base case that stops further recursive calls.

How to Prepare for CS101

Review the current lectures, understand why an answer is correct and practise applying concepts instead of memorising an unofficial answer list. When an online study guide conflicts with official course material, follow the current official material.