Answer to Question 1
Swap space is a file or defined space on the HDD to which data is written, or swapped, to free RAM for applications that are in use.
Answer to Question 2
The two main types of evidentiary computer data are visible data and latent data. Visible data includes all information that the operating system is presently aware of, and thus is readily accessible to the user. Latent data includes data that are blocked from a user's view.