What is a Contra Entry? How is Contra Entry distinguished froth other entries?

Contra Entry: 

The term ‘Contra’ refers to the opposite side. When both aspects (Debit and Credit) of a transaction are recorded in the same account but in different columns, each entry whether in the debit side or in the credit side shall be demand to be the contra entry of the other.

Cash deposited into the hank Rs. 10,000. Here, Bank Account is to be debited and Cash Account is to be credited. Debit aspect is to be recorded in the debit side of the Three column Cash-Book (bank column) and credit aspect is to be recorded in the credit side (cash column).

Cash withdrawn from Bank for office use Rs. 10,000. Here, Cash Account is to be debited and Bank Account is to be Credited. Debit aspect is to be recorded in the debit side of the three column Cash Book (bank column) and credit aspect is to be recorded in the credit side (bank column).

In the above two cases Cash should be treated as contra of Bank and Bank‘ s should be treated as contra of Cash.

Contra entries are marked with letter ‘C’ in the Ledger Folio Column. Such entries are not posted in the Ledger as both accounts (i.e., Cash Account and Bank Account) involved appear in the cash book.