DOMAIN 1 — IT Concepts & Terminology

This domain is the foundation of everything in IT.

If students don’t get this, nothing else makes sense.

1.1 Data Types & Units of Data

Bits & Bytes

• Bit (b) = the smallest unit of data (0 or 1)
• Byte (B) = 8 bits
• Kilobyte (KB) = 1,024 bytes
• Megabyte (MB) = 1,024 KB
• Gigabyte (GB) = 1,024 MB
• Terabyte (TB) = 1,024 GB

Why this matters:

If you work in IT, you must read file sizes, memory capacity, storage, and network speeds. It affects hardware choices, upgrades, backup planning, and troubleshooting.

1.2 IPOS Model — How Computers Work

Input → Processing → Output → Storage

• Input: Keyboard, mouse, microphone
• Processing: CPU, GPU
• Output: Monitor, speakers, printers