Number bases cheat sheet
- Binary (2): 0, 1 — used by computers
- Octal (8): 0–7 — Unix file permissions
- Decimal (10): 0–9 — everyday numbers
- Hex (16): 0–9, A–F — color codes, memory addresses
One hex digit = 4 binary bits. So FF = 11111111 = 8 bits = 1 byte = 255 decimal.