Magnetic, optical and solid state storage, their characteristics, cloud storage, and capacity and transfer calculations.
What you will learn
- Name the type of storage a device uses
- Compare storage by capacity, speed, portability, durability, reliability and cost
- Calculate how many files fit and how long a copy takes
Three technologies
- Magnetic (hard disk drives, tape): data is stored as magnetised areas on spinning platters. Large capacity and the lowest cost per gigabyte, but moving parts make it slower and easier to damage.
- Solid state (SSDs, USB sticks, SD cards): data is stored as electrical charges in flash memory. Fast, silent, light and durable, with no moving parts, but more expensive per gigabyte.
- Optical (CD, DVD, Blu-ray): data is stored as pits and lands read by a laser. Cheap to make and post, but small capacity and slow; easily scratched.
Cloud storage keeps files on remote servers reached over the internet: available anywhere and shareable, but it needs a connection and someone else holds your data.
The rest of this lesson and its 7 practice questions are locked.
In this lesson
- Three technologies
- Choosing, and calculating
- Try it: Choose storage
7 practice questions, marked as you go; about 25 minutes in all.
Key terms
Magnetic, Solid state, Optical, Cloud storage
In this unit: Computer systems
The CPU and the fetch-execute cycle step by step, what makes a CPU fast, RAM, ROM and virtual memory, secondary storage, and system software.