0984
Memory and Storage
Hardware · 4 question types
Exam Frequency Analysis
Past paper frequency (2018 to 2024)
This topic accounts for approximately 5% of your exam marks.
stable
Rare
Stable5%
RAM vs ROM and primary vs secondary storage comparisons appear regularly.
Secondary storage falls into three families, each using a completely different physical principle to store binary 1s and 0s.
| Family | Physical principle | Examples |
|---|---|---|
| Magnetic | Polarity of tiny iron particles on a spinning platter | Hard disk drive (HDD), magnetic tape |
| Solid-state (flash) | Trapped charge in tiny transistor cells | SSD, USB flash drive, SD card |
| Optical | Reflective pits and lands burned into a disc and read by a laser | CD, DVD, Blu-ray |
Each family has its strengths and weaknesses. The right choice depends on capacity, speed, cost, portability, durability and the use case.