Advantages of the journal.
(i) It reduces the possibility of errors.
(ii) It provides an explanation of the transaction.
(iii) It provides a chronological (day-to-day) record of all transactions.
Limitations of the journal.
(i) It will be too long, if all transactions are recorded here.
(ii) It is difficult to ascertain the balance each account.

Rules for journalising:

(1) Date: In the first column, the date of the transaction is entered.
(2) Particulars: The debit and credit aspects of the transaction are recorded. The name of .account to be debited is written first, with the word Dr. In the second line, the name of account to be credited is written with the word To, a few space away from the margin of the particular column.
(3) Narration: After writing the journal entry, a brief explanation of the transaction together with necessary details is given in the particulars column within brackets called narration.
(4) Ledger Folio (L.F.): All entries from the journal are posted later into the ledger accounts. The page number or folio number of the ledger, where the posting has been made recorded in the L.F. column. Till such time, this column remains blank.
(5) Debit Column: In this column, the amount to be credited to the account is written.
(6) Credit Column: In this column, the amount to be credited to the account is written.

Accounting Equation is based on dual aspect concept (Debit and Credit). It emphasizes on the fact that every transaction has a two sided effect (i.e.,) on the assets and claims on assets. Always the total claims (those of outsiders and of the proprietors) will be equal to the total assets of the business concern. The claims are also known as equities, are of two types:
(i) Owners equity (capital) and (ii) Outsider's equity (liabilities).
Assets =Equities
Assets =Capital+ Liabilities (A = C + L)
Capital =Assets - Liabilities (C = A - L)
Liabilities =Assets - Capital (L =A - C)

Source Documents: Source documents are the evidence of business transactions which provide information about the nature of the transaction, the date, the. amount and the parties involved in it Transactions are recorded in the books of accounts when they actually take place and they are duly supported by source documents.
According to the verifiable objective evidence principle of accounting, each transaction recorded in the books of accounts should have adequate proof to support it These supporting documents are the written and authentic proof of the correctness of the recorded transactions. These documents are required for audit and tax assessment They also serve as the legal evidence in case of a dispute.
Examples: Cash memos, invoices, bills, receipts, vouchers, bills receivable, bills payable, wage sheets, salary pay acquittance, c~rresp<?ndence, etc.,

Features of double entry system: The following are the features of double entry system.
(i) Every business transaction affects two accounts.
(ii) Each transaction has two aspects (i.e.,) debit and credit.
(Ui) It is based upon accounting assumptions, concepts and principles.
(iv) Helps in preparing trial balance which is a test of arithmetical accuracy in accounting.
(v) Preparation of final accounts will be made easy with the help of trial balance.