Answer:
ssd or hd (you can chose) ssd and hds are bigger file sizes saving for long term data while RAM gives applications a place to store and access data on a short-term basis. It stores the information your computer is actively using so that it can be accessed quickly.
So if you buy RAM you'll get 8-32 GB of ram and if you get ssd or hd you will get around 500 GB- 2 TB (with modern storage devices)