When you're finally working in the industry and you're designing the servers that are going to serve your traffic and store your data, you'll need to decide on the type of disk type to use. HDDs offer a lot of storage very cheap, but may be too slow. SSDs on the other hand are fast - very fast - but get expensive quickly. Often double the cost, in fact.
Your job will be to understand the right option for the work load.
Hard Disk Drives (HDDs) are able to access large amounts of information quickly. From our perspectives, as users, HDDs offer sufficient speeds, but Solid State Drives (SSD) take this speed to the next level. The fastest form factor we current have is NVMe based SSDs.
At the time of writing, HDDs offer a better price/storage ratio, but SSDs are catching up quickly. When you need to store a lot of information than HDDs are likely going to be the better option. If you don't need to store a lot, but you need speed, then SSDs are the better option.
Given enough time (3-5 years), the NVMe SSD will be able to store as much information as an HDD at similar or better prices.
- Use Cases
When you come to provision storage devices in Amazon Web Services (AWS), you'll need to decide what type of storage device (disk) you need. In most cases, standard HDD technologies are going to be perfectly fine for your use cases. SSDs, however, are excellent for busy databases.
Now do the self-assessment and your project work.