While IT professionals are familiar with many of these special terms and acronyms associated with data storage, this glossary provides a comprehensive list of about two dozen key items  

http://www.networkcomputing.com/storage/data-storage-terms-you-should-know/1781341645

In the last couple of years, the IT industry has created more acronyms than the US government. I won’t even get started on all the “as-a-Service” terms! Storage isn’t immune to acronym overload. Of course, most of the acronyms hide valid technical advances and there have been a lot of those in the storage industry of late.  Today, the storage industry is changing faster than it ever has in the past, so expect there to be even more terminology to keep track of in the near future.  Let’s first look at the types of storage drives available today.

Hard-disk drive: HDDs are the traditional spinning drives that we’ve had for decades. They come in two main sizes, 3.5” diameter media and 2.5” diameter media, with the latter much thinner as well as smaller in area.

Solid-state drive: SSDs are rapidly replacing hard HDDs in the primary storage tier. Unlike HDDs, these drives have no moving parts and store data on flash memory chips. SSDs also are much faster than HDDs, between 100x and 1000x times faster