Vivster is absolutely on the money.
The lines can be blurred when we start using Ram has a hard drive and a hard drive as Ram.
Essentially a computing system has a hierarchy of memories from fastest+smallest capacity to slowest+largest capacity.
Why do we do this? Cost. That's it. Otherwise we would have entire systems with just L1 cache and nothing else.
And by going with a hierarchy we can mitigate performance penalties.
We go from CPU L1 to L2 to L3 caches which are also in order of size and speed. (Smallest+Fastest)
Then (sometimes) you get L4/eDRAM/eSRAM which is another step up in terms of size, but also a step down in speed.
Ram comes next.... And then your Solid State Drive/Hard Drive... And then lastly your Optical Disk.
The SSD simply is an increase in hard drive bandwidth and latency over the older mechanical drives, it doesn't replace Ram, Ram is still orders of magnitude superior in every single way, except in regards to capacity and being volatile.
--::{PC Gaming Master Race}::--
