2 English for Information Technology A2-B1 Vocational English Teacher’s Book

internal components and storage. Note that storage 

is different from memory in that it keeps its data 

after being switched off, unlike most forms of 

memory, which lose data after being switched off. 

Most storage components can be internal or external 

(peripherals), though nowadays external optical 

drives are rare. 

Below are explanations of some of the items 

mentioned: 

• A 

hard disk drive (HDD) is a storage device  

 

that holds its data on spinning magnetised  

 

disks. At the time of writing, these were  

 

beginning to be replaced by solid state drives  

 

(SSDs), which perform a similar function but  

 

without moving parts. 

• Optical 

drive is a generic name for devices that 

 

read and write data from CDs, DVDs or 

 

Blu-ray. The name derives from the fact that 

 

they use a laser, which is an optical device. 

• While