Memory vs. storage – the difference explained
Often, when we discuss the capacity of a type of storage media, we will refer to the amount of data that it can store as its memory. Whilst it would be perfectly clear what someone meant if they made such a claim and, furthermore, it is widely deemed to be an acceptable – if colloquial – description, the word ‘memory’ actually refers to something different. Similar, but different nevertheless!
Storage media such as hard drives, SSDs etc. store data and it would therefore be technically correct to state that they have a storage capacity of 4TBs, for example. Memory, like data storage space, is measured in the same way (i.e. megabytes, gigabytes and so on) but does not actually store data permanently. Rather, it is what your device uses to display whatever you have open at any given time, along with changes that you make to it.
Imagine if you’re working on a report in word. You’ve saved your progress and you shut your computer down. Whilst you were working on the document, it was your computer’s memory (Random Access Memory or RAM for short) that kept the document open and actually stored the changes that you made in real time. When you then clicked on save, you stored the document to your device’s storage media.
Following this, when you located, opened and continued to work on the file, you were, once again, using your device’s memory. When you saved it, you used your device’s storage media.
So, data that you have saved can often be recovered following the storage device having failed because it has been stored on the device in some capacity and can be found by professionals as a result. It is nigh-on impossible to perform data recovery successfully when the data was present on a device's memory only.