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1. Boolean Logic

   • Transistor: An electronic switch which can be either be on or off.
   • Logic Gate: A series of transistors connected to create an output and behave in a certain way.
   • Truth Table: A table which shows outputs from a logic gate or circuit given certain inputs.
   • AND: Q = A ^ B
   • OR: Q = A V B
   • NOT: Q = ¬A

2. Number Representation

   • Binary: Numbering system which uses base 2 (0s & 1s) – the only language that computers understand. 0 means off, 1 means on.
   • Denary: Numbering system which uses base 10 (0-9) – these are our normal numbers that we use every day.
   • Hezadecimal: Base 16 numbering system (0-9 and A-F). Used to represent colours and code in assembly language.
   • Overflow: If you cannot represent a number in the given amount of space (IE more bits are needed to represent a number), then this is an overflow error.
   • Binary Shift: Moving bits within a binary number in a certain direction. Any empty positions are filled with 0. Shifting left doubles a numbers value, shifting right halves its value.
   • Bit The smallest amount of data (binary digit). Byte (B) 8 bits Kilobyte (KB) 1024 bytes Megabyte (MB) 1024 kilobytes Gigabyte (GB) 1024 megabytes Terabyte (TB) 1024 gigabytes Petabyte (PB) 1024 terabytes
   • Binary addition rules 0 + 0 = 0, 1 + 0 = 1 ,0 + 1 = 1, 1 + 1 = 0, carry 1, 1 + 1 + 1 = 1, carry 1

3. CPU

   • CPU: The central processing unit fetches, decodes and executes programs stored in memory, whilst co-ordinating all activity within a computer.
   • Clock Speed: The number of instructions a processor can carry out each second. Measured in Gigahertz (GHz).
   • Core: An individual processing unit within the processor.
   • Cache: A small area of fast access memory inside the CPU.
   • Bus: A connection used to transport data between the CPU and memory.
   • Control Unit (CU): Part of the CPU which co-ordinates all activities, controls other hardware and decodes instructions.
   • Arithmetic Logic Unit (ALU): Completes arithmetic, logic and shift operations, results are stored in the accumulator.
   • Register: A memory location within the CPU which stores specified data or a memory address.
   • Von Neumann Architecture: The concept which all modern systems use. Shared memory stores instructions and data currently being used.
   • Embedded System: A device, which does not need an operating system and performs a specific task.
   • Registers Memory Address Register (MAR): Holds the address of the instruction or data to be fetched or stored. Memory Data Register (MDR): Holds actual data or an instruction that is fetched from or waiting to be written to memory. Accumulator: Special purpose fast access memory location within the CPU where the ALU stores results. Program Counter (PC): Holds the memory address of the next instruction to be processed. Current Instruction Register(CIR): Holds the current instruction to be executed which has been fetched from memory and is temporarily held in the MDR before being copied to the CIR.

4. Characters, Image & SOund

   • Character: A single letter, number or symbol. (e.g., A, 1, !)
   • Character set: A set of characters which are all represented by a unique binary number.
   • ASCII: A character set which uses 7 bits per character to represent maximum of 128 characters.
   • Extended ASCII: A character set which uses 8 bits per character to represent a maximum of 256 characters.
   • Unicode: A character set which uses 16 bits per character to represent a maximum of 65,536 characters.
   • Pixel: The individual units (dots) that make up an image.
   • Bit depth: The number of binary digits used to represent each pixel in an image.
   • Resolution: The level of detail in an image, measured in dots per inch (dpi). Metadata
   • Metadata: Additional information about a file such as the type of file, date and time created geolocation.
   • Sampling: The process of converting an analogue sound signal into a digital file containing binary numbers.
   • Sample rate: The number of readings taken from a sound wave each second. Measured in hertz.
   • Sample resolution: The number of bits used to store each sample.
   • Compression: The re-encoding of data so that less bits are used to store it. Usually done to increase speed of transmission.
   • Lossy: Removes data completely to reduce the size of a file (eg. JPG)
   • Lossless: Organises data to reduce the size of a file without removing any information (eg. ZIP)
   • Image File Size: (????ℎ ∗ ℎ???ℎ? ∗ ??? ????ℎ)/8
   • Sound File Size: (?????? ???? ∗ ?????? ?????????? ∗ ???????)/8

5. Hardware

   • Hardware: Computer hardware is the physical parts or components of a computer.
   • Peripheral: An auxiliary device that connects to and works with the computer in some way.
   • Input peripheral: A peripheral device which brings data from the physical world into a computer system.
   • Output peripheral: A peripheral device which brings data from a computer system into the physical world.
   • Storage peripheral: A peripheral device which is used to store data & files.
   • Primary Memory: Memory which can be accessed directly by the CPU. (EG: RAM, ROM)
   • Secondary Storage Memory: which cannot be accessed directly by the CPU. (EG HDD, SSD)
   • Processor: The device which controls all other hardware and executes instructions.
   • GPU: Graphics Processing Unit. Used for processing of graphics, particularly used by gamers and graphic designers.
   • Hard drive HDD: A secondary storage device which holds files and programs.
   • Solid State Drive SSD: A secondary storage device which holds files and programs. This uses solid state technology to store data.
   • Motherboard: Connects all devices to each other in a computer system to allow them to communicate and work with each other.
   • PCI: An expansion port that allows a computers capability to be upgraded. Components that may be upgraded include GPU, sound cards and NICs.
   • PSU: Power Supply Unit. Converts mains AC to low-vo
   • RAM Random Access Memory: A form of primary memory which stores data and instructions for programs which are currently in use. This is volatile