1.2- Memory and Storage

This type of storage cannot be read directly by the CPU. It’s non-volatile and much bigger than primary. Examples are Hard Disk, USB Flash Drive, SSD, CD

This type of storage is also known as main memory or primary memory. It is volatile and can be accessed directly by the CPU

Primary Storage we can write to, also known as main memory. All data in use and instructions currently running are stored here. It is volatile.

Cannot be changed. Non-volatile semiconductor primary memory, contains the start-up instructions for the computer known as the BIOS

Forgets all contents when powered off, RAM is this type

Remembers all contents when powered off, ROM is this type

We can do this to RAM but not ROM, it means change the contents

The startup instructions for a computer, stored in ROM. It stands for Basic Input Output System

Space in secondary storage that acts like extra RAM, so we can run more processes simultaneously

Any part of a program that is currently running, this will need to be in primary memory so the CPU can execute it

Moving a process from RAM to virtual memory to make more room in RAM for a new process

Constantly swapping processes between RAM and virtual memory because there is not enough RAM. Causes slow performance.

Currently executing. (A process must be loaded in RAM before it can be executed)

How fast a secondary storage device can read and write data. SSDs and flash memory are fast

Ability of a device to withstand knocks and drops and still work, solid state devices are good

How long a secondary storage device will last without breaking down or losing data, solid state devices are good at this

The price of a secondary storage device, SSDs are high

How easy it is to move a secondary storage device or its media around, CDs and memory sticks have this

High capacity magnetic secondary storage device. It has spinning platters so it wears out, making it less reliable and portable than SSD.

Optical storage, a laser reads and writes the 700MB capacity optical disks. Disks are cheap and portable.

Optical storage, a laser reads and writes the 4.7GB capacity optical disks which are cheap and portable, but a bit more expensive than CDs.

An optical storage component with a capacity of 25GB, a blue laser reads them, they are more expensive than DVDs but still cheap to make.

No moving parts means this high capacity, fast, durable, low power and reliable secondary storage device is good for laptops but it’s expensive

A solid state storage removable storage device which is very portable, comes in capacities from 1GB up to 512GB