A raw item is an original file.
An edit session is a virtual file.
Several types of edited item exist (depending on the tool you use for editing).
The different edited icons :
: edited item coming from the "Snippet" tab.
: edited item coming from the "Multitrack" or "Snippet+" tabs.
: edited item (called "produced item") coming from the "Production" tab.
Attention : Do not transform a "produced" item into a Master, otherwise you will loose the information that you have put on the sound.
A master is the transformation of a edited file into a real sound.