[Description] Volatile data can be read. Before a transaction modifies data, it verifies if another transaction has changed the data after it was initially read. If the data has been updated, an error is raised. This allows a transaction to get to the previously committed value of the data. When you try to promote a transaction that was created with this isolation level, an InvalidOperationException is thrown with the error message "Transactions with IsolationLevel Snapshot cannot be promoted". [Member name] 
Snapshot
S e r i a l i z a b l e
R e p e a t a b l e R e a d
R e a d C o m m i t t e d
R e a d U n c o m m i t t e d
S n a p s h o t
C h a o s
U n s p e c i f i e d