IBDP CS 2025

A1. Computer fundamentals
A1.1 Computer hardware and operation
9 Topics
A1.1.1 Describe the functions and interactions of the main CPU components
A1.1.2 Describe the role of a GPU
A1.1.3 Explain the differences between the CPU and the GPU (HL only)
A1.1.4 Explain the purposes of different types of primary memory
A1.1.5 Describe the fetch, decode and execute cycle
A1.1.6 Describe the process of pipelining in multi-core architectures (HL only)
A1.1.7 Describe internal and external types of secondary memory storage
A1.1.8 Describe the concept of compression
A1.1.9 Describe the different types of services in cloud computing
A1.2 Data representation and computer logic
5 Topics
A1.2.1 Describe the principal methods of representing data
A1.2.2 Explain how binary is used to store data
A1.2.3 Describe the purpose and use of logic gates
A1.2.4 Construct and analyse truth tables
A1.2.5 Construct logic diagrams
A1.3 Operating systems and control systems
7 Topics
A1.3.1 Describe the role of operating systems
A1.3.2 Describe the functions of an operating system
A1.3.3 Compare different approaches to scheduling
A1.3.4 Evaluate the use of polling and interrupt handling
A1.3.5 Explain the role of the operating system in managing multitasking and resource allocation (HL only)
A1.3.6 Describe the use of the control system components (HL only)
A1.3.7 Explain the use of control systems in a range of real-world applications (HL only)
A1.4 Translation (HL only)
1 Topic
A1.4.1 Evaluate the translation processes of interpreters and compilers
A2. Networks
A2.1 Network fundamentals
5 Topics
A2.1.1 Describe the purpose and characteristics of networks
A2.1.2 Describe the purpose, benefits and limitations of modern digital infrastructures
A2.1.3 Describe the function of network devices
A2.1.4 Describe the network protocols used for transport and application
A2.1.5 Describe the function of the TCP/IP model (HL only)
A2.2 Network architecture
4 Topics
A2.2.1 Describe the functions and practical applications of network topologies
A2.2.2 Describe the function of servers (HL only)
A2.2.3 Compare and contrast networking models
A2.2.4 Explain the concepts and applications of network segmentation
A2.3 Data Transmissions
4 Topics
A2.3.1 Describe different types of IP addressing
A2.3.2 Compare types of media for data transmission
A2.3.3 Explain how packet switching is used to send data across a network
A2.3.4 Explain how static routing and dynamic routing move data across local area networks (HL only)
A2.4 Network security
4 Topics
A2.4.1 Discuss the effectiveness of firewalls at protecting a network
A2.4.2 Describe common network vulnerabilities (HL only)
A2.4.3 Describe common network countermeasures (HL only)
A2.4.4 Describe the process of encryption and digital certificates
A3. Databases
A3.1 Database fundamentals
1 Topic
A3.1.1 Explain the features, benefits and limitations of a relational database
A3.2 Database design
7 Topics
A3.2.1 Describe database schemas
A3.2.2 Construct ERDs
A3.2.3 Outline the different data types used in relational databases
A3.2.4 Construct tables for relational databases
A3.2.5 Explain the difference between normal forms
A3.2.6 Construct a database normalized to 3NF for a range of real-world scenarios
A3.2.7 Evaluate the need for denormalizing databases
A3.3 Database programming
6 Topics
A3.3.1 Outline the differences between data language types within SQL
A3.3.2 Construct queries between two tables in SQL
A3.3.3 Explain how SQL can be used to update data in a database
A3.3.4 Construct calculations within a database using SQL’s aggregate functions (HL only)
A3.3.5 Describe different database views (HL only)
A3.3.6 Describe how transactions maintain data integrity in a database (HL only)
A3.4 Alternative databases and data warehouses (HL only)
4 Topics
A3.4.1 Outline the different types of databases as approaches to storing data
A3.4.2 Explain the primary objectives of data warehouses in data management and business intelligence
A3.4.3 Explain the role of online analytical processing (OLAP) and data mining for business intelligence
A3.4.4 Describe the features of distributed databases
A4. Machine Learning
A4.1 Machine learning fundamentals
2 Topics
A4.1.1 Describe the types of machine learning and their applications in the real world
A4.1.2 Describe the hardware requirements for various scenarios where machine learning is deployed
A4.2 Data preprocessing (HL only)
3 Topics
A4.2.1 Describe the significance of data cleaning
A4.2.2 Describe the role of feature selection
A4.2.3 Describe the importance of dimensionality reduction
A4.3 Machine learning approaches (HL only)
10 Topics
A4.3.1 Explain how linear regression is used to predict continuous outcomes
A4.3.2 Explain how classifications techniques in supervised learning are used to predict discrete categorical outcomes
A4.3.3 Explain the role of hyperparameter tuning when evaluating supervised learning algorithms
A4.3.4 Describe how clustering techniques in unsupervised learning are used to group data based on similarities in features
A4.3.5 Describe how learning techniques using the association rule are used to uncover relations between different attributes in large data sets
A4.3.6 Describe how an agent learns to make decisions by interacting with its environment in reinforcement learning
A4.3.7 Describe the application of genetic algorithms in various real-world situations
A4.3.8 Outline the structure and function of ANNs and how multi-layer networks are used to model complex patterns in data sets
A4.3.9 Describe how CNNs are designed to adaptively learn spatial hierarchies of features in images
A4.3.10 Explain the importance of model selection and comparison in machine learning
A4.4 Ethical considerations
2 Topics
A4.4.1 Discuss the ethical implications of machine learning in real-world scenarios
A4.4.2 Discuss ethical aspects of the increasing integration of computer technologies into daily life
B1. Computational thinking
B1.1 Approaches to computational thinking
4 Topics
B1.1.1 Construct a problem specification
B1.1.2 Describe the fundamental concepts of computational thinking
B1.1.3 Explain how applying computational thinking to fundamental concepts is used to approach and solve problems in computer science
B1.1.4 Trace flowcharts for a range of programming algorithms
B2. Programming
B2.1 Programming fundamentals
4 Topics
B2.1.1 Construct and trace programs using a range of global and local variables of various data types
B2.1.2 Construct programs that can extract and manipulate substrings
B2.1.3 Describe how programs use common exception handling techniques
B2.1.4 Construct and use common debugging techniques
B2.2 Data structures
4 Topics
B2.2.1 Compare static and dynamic data structures
B2.2.2 Construct programs that apply arrays and Lists
B2.2.3 Explain the concept of a stack as a “last in, first out” (LIFO) data structure
B2.2.4 Explain the concept of a queue as a “first in, first out” (FIFO) data structure
B2.3 Programming constructs
4 Topics
B2.3.1 Construct programs that implement the correct sequence of code instructions to meet program objectives
B2.3.2 Construct programs utilizing appropriate selection structures
B2.3.3 Construct programs that utilize looping structures to perform repeated actions
B2.3.4 Construct functions and modularization
1 of 2
Previous Topic
Next Topic

A1.1.5 Describe the fetch, decode and execute cycle

IBDP CS 2025 A1.1 Computer hardware and operation A1.1.5 Describe the fetch, decode and execute cycle

TEXT

TEXT

Interactive Animation
https://www.hartismere.com/Curriculum/Computer-Science/CPU-Fetch-Decode-Execute-Animation

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

TEXT

TEXT

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

Worked Example

Question: The instructions X, Y ,X add values J, K. Describe the fetch, decode, and execute phases, step by step.

Answer:

Step 1.

Step 2.

Step 3.

…

Previous Topic
Back to Lesson
Next Topic