A self-paced introduction to the core ideas of computer science for complete beginners and career changers. Eight lessons take you from bits and bytes through hardware, operating systems, algorithms, data structures, complexity, networking and your first steps in programming, with a practical exercise at the end of every lesson.
What you will learn
- Explain how computers represent numbers, text and images in binary
- Describe the roles of the CPU, memory, storage and operating system
- Read and design simple algorithms and compare their efficiency
- Choose sensible data structures for common problems
- Understand what happens when you load a web page
Lessons
- What Computer Science Actually Is
- Binary, Bits and How Data Is Represented
- Hardware: CPU, Memory and Storage
- Operating Systems and Software Layers
- Algorithms and Problem Solving
- Data Structures
- Efficiency and Big O Notation
- Networks, the Internet and Your First Program
Self-paced course from Tech Skills Library. Educational content only. Completing the course earns a Certificate of Completion, not an accredited qualification, licence or credential.
Lessons
What Computer Science Actually Is
Binary, Bits and How Data Is Represented
Every piece of information inside a computer, whether it is a number, a letter, a photo or a song, is ultimately stored as a pattern of bits. A bit is a single binary digit that can be either 0 or 1. Physically, a bit might be a high or low voltage, a magnetised or unmagnetised […]
Hardware: CPU, Memory and Storage
A computer is a machine that follows instructions to transform input into output. Although devices range from phones to data-centre servers, nearly all of them share the same basic architecture, first described in the 1940s and still known as the von Neumann model. It consists of a processor that executes instructions, memory that holds the […]
Operating Systems and Software Layers
Hardware on its own can only follow raw machine instructions. The operating system is the layer of software that turns a collection of chips into a usable computer. Windows, macOS, Linux, Android and iOS are all operating systems. They manage hardware resources, provide services that applications rely on, and present an interface to the person […]
Algorithms and Problem Solving
An algorithm is a finite, precise sequence of steps that solves a problem or completes a task. Recipes, assembly instructions and driving directions are everyday algorithms, but computer algorithms must be completely unambiguous because a machine cannot guess what you meant. Designing algorithms is the core creative activity in computer science. Properties of a good […]
Data Structures
Algorithms work on data, and the way data is organised has a huge effect on how easy and fast an algorithm is. A data structure is a particular way of storing and organising data so that certain operations, such as finding, adding or removing items, are efficient. Choosing the right data structure is often more […]
Efficiency and Big O Notation
Two algorithms can both be correct yet behave very differently as the amount of data grows. Searching a list of ten names takes no noticeable time with any method, but searching a billion records can take milliseconds with one approach and hours with another. Computer scientists describe this difference using Big O notation, a way […]
Networks, the Internet and Your First Program
Most computing today happens across networks. When you open a web page, your device cooperates with routers, servers and protocols spread across the world. This final lesson explains how that works and then introduces the programming concepts you will use in any language. How the internet moves data The internet is a network of networks. […]