MATSEC AM Information Technology cheat sheet
MATSEC AM Information Technology · Keep the key ideas within reach.
Information Technology - Core Reference
Data vs information: data are raw unprocessed symbols (e.g. 39.5); information is data processed into a meaningful, decision-useful form (e.g. "patient temperature 39.5 °C, above normal range").
System components: input → processing → output, with storage and feedback as supporting elements; a system boundary separates the system from its environment.
Hardware categories: input devices, output devices, processing (CPU: control unit, ALU, registers), primary storage (RAM volatile, ROM non-volatile), secondary storage (magnetic, optical, solid-state).
Storage capacity units: 1 byte = 8 bits; 1 KiB = 1024 bytes; 1 MiB = 1024 KiB; 1 GiB = 1024 MiB; 1 TiB = 1024 GiB.
Software classes: system software (OS, utilities, drivers) manages hardware and provides a platform; application software (general-purpose vs bespoke) performs user tasks.
OS functions: process management, memory management, file management, device management via drivers, security/access control, and the user interface (CLI or GUI).
Networks: LAN (single site, high speed, privately owned) vs WAN (geographically dispersed, often leased); topologies star, bus, ring, mesh; the Internet is a public WAN.
Data protection: backup (full, incremental, differential), RAID for redundancy, UPS for power continuity, and access control (authentication plus authorisation) for confidentiality.
Number systems: binary base 2, denary base 10, hexadecimal base 16; conversions use repeated division by the target base (remainders read upwards) or positional weighting.