Which memory is which?

The biggest factors in consumer confusion when buying new computers are usually the functions of the hard disk drive (HDD), random-access memory (RAM) and the central processing unit (CPU).

This simple rundown of each one will help make sure you don’t incur an unnecessary overspend when you buy a new computer.


Usually referred to as the hard drive but sometimes as storage or memory, this component is where everything on your device will be stored. Any photos or videos you download will be saved to this device and the bigger it is, the more you will be able to store. 

Hard drive size is usually measured in gigabytes (GB). To give you an idea of how big a gigabyte is, a 100GB hard drive will store approximately 15,000 songs or 50,000 images. Remember when you’re considering hard drive size that the computer’s software will take up to 30GB to run.


RAM, which is sometimes confusingly also referred to as memory, is quite similar to the hard drive above, but is only used to store things temporarily, while they are in use. 

A great analogy for understanding the difference between RAM and hard drive is that RAM is ‘desk space’ and the hard drive is ‘a filing cabinet’. So your desk is where everything is laid out while you’re working on it, and the bigger the desk is the more you can do at one time, whereas the filing cabinet is where everything is stored while it’s not on your desk, but you can bring it out whenever you would like. 

RAM is also measured in gigabytes and most people will be able to get by comfortably with 4GB, or if you watch a lot of videos or play games on your computer, you might want to consider 8GB. Anything more than this is likely a waste of money.


The CPU is pretty much the brain of your computer, you can think of it as a virtual person that sits behind the RAM desk and does all the work. CPU speed is measured in hertz or gigahertz (GHz), and the more GHz you have, the faster your computer will do tasks, such as opening new programs or turning on. 

If you don’t use your computer for much other than browsing the internet, then you probably don’t need to get a very powerful CPU, but if you want a quicker computer, a powerful CPU in combination with a large amount of RAM will do the trick. 

Bear in mind that if you’re buying a laptop, a more powerful CPU will mean a shorter battery life.

Written by YourLifeChoices Writers

YourLifeChoices' team of writers specialise in content that helps Australian over-50s make better decisions about wealth, health, travel and life. It's all in the name. For 22 years, we've been helping older Australians live their best lives.

Leave a Reply

What’s on when on the road

Shirley Bassey