Computing Concepts: AQA GCSE Paper 2 Revision
,Paper 2 Exam Overview
Exam Structure Question Types Explanation & Evaluation
Paper 2 is a 1 hour 30 minute Expect a mix of multiple-choice For explanation questions,
theory-based exam, contributing questions (MCQs), short-answer provide clear definitions and
50% to your overall GCSE questions requiring direct recall, logical steps. For evaluation,
Computer Science grade. It tests and longer-answer questions discuss advantages and
your understanding of computing demanding explanation and disadvantages, using specific
concepts through a variety of evaluation skills. Practice all examples to support your points.
question types. formats! Always aim for clarity and
precision.
,Data Representation Fundamentals
Computers process all information as binary data – a series of 0s and 1s. Understanding how different types of data are
represented is crucial.
Number Systems Images, Sound & Compression
Binary (Base 2): Uses only 0s and 1s. The fundamental Images: Composed of pixels (picture elements). Colour
language of computers. depth (number of bits per pixel) determines the
Denary (Base 10): Our everyday number system, using number of colours. Resolution (width x height) is the
digits 0-9. number of pixels. Metadata stores information about
the image (e.g., date, camera model).
Hexadecimal (Base 16): Uses 0-9 and A-F. Often used
as a shorthand for binary, as each hex digit represents Sound: Analogue sound waves are converted to digital
four binary digits (nibble). through sampling. Sample rate (samples per second)
and bit depth (bits per sample) affect quality.
Character Sets Compression: Reduces file size. Lossy compression
permanently removes data (e.g., MP3, JPEG). Lossless
Character sets assign unique binary codes to characters.
compression allows exact reconstruction of original
ASCII: An older standard, using 7 bits to represent 128 data (e.g., PNG, GIF, ZIP).
characters (e.g., 'A' is 01000001).
Unicode: A modern, extensive standard using 16, 24, or
32 bits, representing characters from almost all writing
systems worldwide.
, Computer Systems: Hardware
Understanding the fundamental components of a computer system is key to grasping how software interacts with
hardware.
CPU Components Von Neumann Architecture CPU Performance Factors
ALU (Arithmetic Logic Unit): A design where program Clock Speed: The number of
Performs calculations and instructions and data are stored in cycles the CPU executes per
logical operations. the same memory space, accessed second (e.g., GHz).
CU (Control Unit): Manages by a single bus. This is the basis Cache: Small, fast memory
and coordinates all CPU for most modern computers. near the CPU for frequently
operations. accessed data.
Registers: Small, high-speed Cores: Multiple processing
storage locations within the units within a single CPU,
CPU. allowing for parallel
processing.
Primary Storage Secondary Storage
RAM (Random Access Memory): Volatile, Non-volatile storage for long-term data retention.
temporary storage for currently running programs
SSD (Solid State Drive): Uses flash memory, fast,
and data. Faster access.
durable, no moving parts.
ROM (Read Only Memory): Non-volatile, stores
HDD (Hard Disk Drive): Uses spinning platters,
essential boot-up instructions (BIOS). Cannot be
slower, mechanical parts, higher capacity for cost.
easily altered.
Optical Storage: CDs, DVDs, Blu-rays. Uses lasers
to read/write data.
Flash Storage: USB sticks, SD cards. Compact,
portable, uses solid-state technology.
,Paper 2 Exam Overview
Exam Structure Question Types Explanation & Evaluation
Paper 2 is a 1 hour 30 minute Expect a mix of multiple-choice For explanation questions,
theory-based exam, contributing questions (MCQs), short-answer provide clear definitions and
50% to your overall GCSE questions requiring direct recall, logical steps. For evaluation,
Computer Science grade. It tests and longer-answer questions discuss advantages and
your understanding of computing demanding explanation and disadvantages, using specific
concepts through a variety of evaluation skills. Practice all examples to support your points.
question types. formats! Always aim for clarity and
precision.
,Data Representation Fundamentals
Computers process all information as binary data – a series of 0s and 1s. Understanding how different types of data are
represented is crucial.
Number Systems Images, Sound & Compression
Binary (Base 2): Uses only 0s and 1s. The fundamental Images: Composed of pixels (picture elements). Colour
language of computers. depth (number of bits per pixel) determines the
Denary (Base 10): Our everyday number system, using number of colours. Resolution (width x height) is the
digits 0-9. number of pixels. Metadata stores information about
the image (e.g., date, camera model).
Hexadecimal (Base 16): Uses 0-9 and A-F. Often used
as a shorthand for binary, as each hex digit represents Sound: Analogue sound waves are converted to digital
four binary digits (nibble). through sampling. Sample rate (samples per second)
and bit depth (bits per sample) affect quality.
Character Sets Compression: Reduces file size. Lossy compression
permanently removes data (e.g., MP3, JPEG). Lossless
Character sets assign unique binary codes to characters.
compression allows exact reconstruction of original
ASCII: An older standard, using 7 bits to represent 128 data (e.g., PNG, GIF, ZIP).
characters (e.g., 'A' is 01000001).
Unicode: A modern, extensive standard using 16, 24, or
32 bits, representing characters from almost all writing
systems worldwide.
, Computer Systems: Hardware
Understanding the fundamental components of a computer system is key to grasping how software interacts with
hardware.
CPU Components Von Neumann Architecture CPU Performance Factors
ALU (Arithmetic Logic Unit): A design where program Clock Speed: The number of
Performs calculations and instructions and data are stored in cycles the CPU executes per
logical operations. the same memory space, accessed second (e.g., GHz).
CU (Control Unit): Manages by a single bus. This is the basis Cache: Small, fast memory
and coordinates all CPU for most modern computers. near the CPU for frequently
operations. accessed data.
Registers: Small, high-speed Cores: Multiple processing
storage locations within the units within a single CPU,
CPU. allowing for parallel
processing.
Primary Storage Secondary Storage
RAM (Random Access Memory): Volatile, Non-volatile storage for long-term data retention.
temporary storage for currently running programs
SSD (Solid State Drive): Uses flash memory, fast,
and data. Faster access.
durable, no moving parts.
ROM (Read Only Memory): Non-volatile, stores
HDD (Hard Disk Drive): Uses spinning platters,
essential boot-up instructions (BIOS). Cannot be
slower, mechanical parts, higher capacity for cost.
easily altered.
Optical Storage: CDs, DVDs, Blu-rays. Uses lasers
to read/write data.
Flash Storage: USB sticks, SD cards. Compact,
portable, uses solid-state technology.
