DQM Basic Units
Information and Communication Technology Skills cheat sheet
Every chapter's key points, formulas and definitions on one page, for the last week before the exam. Each heading links to the chapter that explains it.
Computer hardware and software
- ICT covers the hardware, software, networks and systems used to create, store, process and exchange information, combining computing (data processing) with telecommunications (data transmission).
- Its functions are data capture and storage, processing data into information, communication, automation of repetitive tasks and decision support.
- Each generation of computers, from vacuum tubes through transistors, integrated circuits and microprocessors to artificial intelligence, made computers smaller, faster, more reliable and cheaper.
- The components work as a cycle: input devices capture data, memory holds it while the CPU runs the instructions, output devices present the results and storage keeps them, with the motherboard linking all of them.
- Choosing hardware and software starts from the work: the tasks, users, data volumes, existing systems, total cost of ownership and vendor support. Software is usually chosen first.
Key terms
- First generation
- Vacuum-tube machines, large, slow and power-hungry.
- Second generation
- Transistor-based, smaller and more reliable.
- Third generation
- Integrated circuits, a major leap in speed and size reduction.
- Fourth generation
- Microprocessors, giving rise to the personal computer.
- Fifth generation
- Emphasis on artificial intelligence and parallel processing.
- Central Processing Unit (CPU)
- Executes instructions, the computer's core processor.
- Memory (RAM)
- Temporary, fast storage the CPU works from while a program runs.
- Storage devices
- Hard disks, SSDs and removable media that hold data permanently.
- Input devices
- Keyboard, mouse, scanner: bring data into the system.
- Output devices
- Monitor, printer, speakers: present processed information.
- Motherboard
- Connects and coordinates all the other components.
- Supercomputers
- The fastest, most powerful class, used for intensive scientific computation.
- Mainframe computers
- Large systems processing high volumes of transactions reliably.
- Minicomputers
- Mid-range machines, smaller than mainframes, once common in departments.
- Microcomputers (personal computers)
- Desktops and laptops for individual use.
- Mobile devices
- Smartphones and tablets, now a common computing platform in their own right.
The rest of the sheet covers
- Information security
- Processing data with applications
- Networks and the internet
- Exam technique and revision
- Glossary