This refers to any form of communication received from the bank. For ex: A letter intimating change in minimum balance to be maintained can be considered a bank correspondence.
The different means by which banks accept deposits are: As cash at their branches As checks at their branches As cash through their ATMs As checks through their ATMs As fund transfers from other banks
CR means a credit has been applied to your account (ie, money returned to you). Credits are expenses for the banks, so they are tallied as expenses on their financial documents.
Usually it means that people lack confidence in the back and withdraw their money - which means that more people lose confidence in the bank and withdraw their money and so on.