Journal
A journal is a chronological (arranged in order of time) record of business transactions. A journal entry is the recording of a business transaction in the journal. A journal entry shows all the effects of a business transaction as expressed in debit(s) and credit(s) and may include an explanation of the transaction. A transaction is entered in a journal before it is entered in ledger accounts. Because each transaction is initially recorded in a journal rather than directly in the ledger, a journal is called a book of original entry.
Creating a journal does not have any effect until it is posted in General ledger.
Once a journal is posted , it cannot be changed . The only way to eliminate the transaction is to reverse the original transaction by creating a reverse journal and posting into general ledger.