What about the data?
In this chapter so far, we've looked at the various media for storing data. Now, I'd like to talk about the actual data itself, some of its states, and what happens when it's accessed.
Data states
Firstly, there's data in transit, also called data in motion. These states describe data on the move, perhaps traversing across the network between devices or even between storage media, actively moving between locations.
Then there's data in use. Data in this state is currently being accessed by a user or processed by a CPU. When data is accessed from the hard drive, it is temporarily stored in RAM, which is much faster than the hard drive (particularly mechanical drives) and stored there for as long as the user accesses it and there is power to the device.
When data is not in motion, transit, or in use, it is described as data at rest. In this state, the data rests or resides on non-volatile media such as hard drives, optical media...
