Consistency simply means that each user sees the consistent view of the data.
Consider an example: there are two users A and B. A transfers money to B's account. Here the changes are updated in A's account (debit) but until it will be updated to B's account (credit), till then other users can't see the debit of A's account. After the debit of A and credit of B, one can see the updates. That?s consistency.
