Answer: Storage devices are non-volatile devices. That means that when the power is removed from them, for example, when you switch your computer off, they retain their contents (unlike RAM, which is volatile – it loses its contents). You can then retrieve the contents next time you switch your computer on. Storage devices can be used to hold operating systems, applications and files, amongst other types of software. They are simply big suitcases – used only for storage. We have already seen that when you want to use an application kept on a storage device, it has to be moved to RAM before you can start using it. This applies to the operating system, your files and any other category of software. For this reason, RAM is sometimes known as Primary Memory whereas storage devices are often referred to as Secondary Storage devices.