CAMS Level I
Fundamentals of ICT 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.
Foundations of computing
- Data is unprocessed facts; it becomes information once it is arranged, summarised or interpreted for a specific reader.
- A bit is a single 0 or 1 and a byte is eight bits; storage climbs in steps of 1,024, from bytes to KB, MB and GB.
- A computer system needs five elements working together: hardware, software, data, procedures and people. Take any one away and the rest cannot produce output.
- Hardware is what can be touched, software is the programs, procedures and data that instruct it, and a program is one set of instructions for one specific job.
- Computers fall into five generations, from vacuum tubes to artificial intelligence, and are classified by size, by type (analog, digital, hybrid) and by purpose (general or special).
Key terms
- Data
- Unprocessed facts on their own, a stock count of 340 units, a customer's phone number, a date, none of which tells its reader anything useful until it is arranged and interpreted.
- Information
- The output once data has been arranged, summarised or interpreted for a specific reader, a stock count of 340 units becomes information the moment it is compared against a reorder level and flagged as low.
- Bit
- The smallest unit a machine can hold, a single binary digit fixed at either 0 or 1.
- Byte
- Eight bits grouped together, the unit storage capacity is actually quoted in. The scale climbs in steps of 1,024: 1,024 bytes make a kilobyte (KB), 1,024 KB make a megabyte (MB), and 1,024 MB make a gigabyte (GB).
- User
- Anyone operating the machine directly, typing in a figure, running a report, or pulling data back out of it.
- Digital
- Built entirely from discrete 0/1 values, in contrast to an analog signal, which varies smoothly and continuously rather than switching between fixed states.
- Supercomputer
- Sits at the top of the scale on cost, speed and physical size alike, built for work no ordinary machine could finish in useful time, climate modelling and large-scale scientific simulation among its typical jobs.
- Mainframe
- A large-organisation workhorse, built to hold and process very high transaction volumes centrally, the kind of machine sitting behind a bank's core ledger.
- Minicomputer
- A step down from a mainframe in raw power, but still able to serve several users working at once, usually sized to one department rather than a whole institution.
- Microcomputer
- Built around one microprocessor and by far the most common size in everyday use, the desktop, laptop, tablet and smartphone all belong here.
- Analog computer
- Works directly on a physical quantity that varies smoothly, voltage, temperature or pressure, chiefly found in scientific and industrial measurement instruments.
- Digital computer
- Works only on discrete binary values, the type this whole paper is built around from here on.
- Hybrid computer
- Takes an analog reading in (a continuous signal from a sensor) and switches to digital processing on it, the pattern behind equipment such as a hospital ECG monitor.
- General purpose computer
- Built to be repurposed by whatever program is loaded onto it, accounting today, a game tomorrow, the category nearly every desktop and laptop falls into.
- Special purpose computer
- Built and permanently programmed for exactly one job, the embedded controller inside an ATM or a washing machine, for instance, and nothing beyond it.
The rest of the sheet covers
- Computer hardware
- Computer software and operating systems
- Application software
- Computer networks
- Securing data
- Exam technique and revision
- Glossary