GCSE Computer Science Syllabus

Computer Science syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Computer Science in GCSE, not a summary of it.

1. 1

   Fundamentals of Algorithms

   4 topics

   • Understanding Algorithms
   • Pseudo-code and Flowcharts
   • Searching Algorithms
   • Sorting Algorithms
2. 2

   Programming

   5 topics

   • Programming Basics
   • Data Types
   • Control Structures
   • Subroutines and Functions
   • Error Handling
3. 3

   Data Representation

   4 topics

   • Binary Systems
   • Hexadecimal
   • Data Storage
   • Compression
4. 4

   Computer Systems

   4 topics

   • Hardware and Software
   • Memory and Storage
   • System Architecture
   • Network Topologies
5. 5

   Networks

   4 topics

   • Types of Networks
   • Network Protocols
   • Network Security
   • Internet and WWW
6. 6

   Cyber Security

   4 topics

   • Threats to Data
   • Preventing Vulnerabilities
   • Social Engineering
   • Malware
7. 7

   Ethical, Legal and Environmental Impacts of Digital Technology

   4 topics

   • Ethical Issues
   • Legal Issues
   • Environmental Issues
   • Privacy Issues

Computer Science flashcards for GCSE

23 of 56 cards from the Computer Science deck — real questions with worked answers.

1. What is an algorithm?

   A step-by-step sequence of precise, unambiguous instructions to solve a problem or complete a task.

2. What is decomposition in computational thinking?

   Breaking a large, complex problem down into smaller, more manageable sub-problems that are easier to solve.

3. What is abstraction in computational thinking?

   Removing or hiding unnecessary detail so that only the information relevant to solving the problem remains.

4. In flowcharts, what does a rectangle (box) represent?

   A process or instruction (an action being carried out).

5. In flowcharts, what does a diamond (rhombus) represent?

   A decision, where a Yes/No or True/False question determines which path is followed.

6. In flowcharts, what do the parallelogram and the rounded rectangle (terminator) represent?

   The parallelogram represents input/output; the rounded rectangle (stadium shape) represents the start or stop terminator.

7. What is pseudo-code?

   A structured but informal way of describing an algorithm using plain, code-like statements that are independent of any specific programming language.

8. How does a linear (serial) search work?

   It checks each item in the list one at a time from the start until the target is found or the end of the list is reached.

9. How does a binary search work?

   It repeatedly checks the middle item of a sorted list, discarding the half that cannot contain the target, until the item is found.

10. What is a key requirement of binary search that linear search does not need?

    The list must already be sorted into order.

11. Compare the efficiency of binary search and linear search on large sorted lists.

    Binary search is far faster because it halves the search space each step ($O(\log_2 n)$), whereas linear search checks items one by one ($O(n)$).

12. How does a bubble sort work?

    It repeatedly steps through the list, comparing adjacent items and swapping them if they are in the wrong order, until a full pass makes no swaps.

13. How does a merge sort work?

    It uses divide-and-conquer: the list is repeatedly split in half until single items remain, then the halves are merged back together in order.

14. How does an insertion sort work?

    It builds a sorted section one item at a time, taking the next item and inserting it into its correct position among the already-sorted items.

15. Which is generally more efficient for large lists, bubble sort or merge sort, and why?

    Merge sort, because its time complexity is $O(n \log n)$ compared with bubble sort's $O(n^{2})$.

16. What is a variable in programming?

    A named location in memory that stores a value which can change while the program runs.

17. What is a constant in programming?

    A named value that is set once and cannot be changed while the program runs.

18. Name the three basic programming constructs.

    Sequence, selection, and iteration.

19. What is the difference between iteration and selection?

    Iteration repeats a block of code (loops); selection chooses which block of code to run based on a condition (IF/ELSE).

20. What is the difference between a count-controlled loop and a condition-controlled loop?

    A count-controlled loop (FOR) repeats a fixed number of times; a condition-controlled loop (WHILE) repeats until a condition changes.

21. List the common primitive data types used in programming.

    Integer, real/float, Boolean, character, and string.

22. What data type would you use to store the value True or False?

    Boolean.

23. What is the difference between an integer and a real (float) data type?

    An integer stores whole numbers only; a real/float stores numbers with a decimal (fractional) part.

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