Double-entry accounting requires two entries for every transaction: one to show the decrease and one to show the opposing and equal increase. These two entries are referred to as debit and credit. However, the terms only mean left (debit) and right (credit). In manual accounting systems, each account is a ‘T’ with entries on the left side showing debits to the account and entries on the right side showing credits to the account.

It is important to remember that debit does not always mean decrease and credit mean increase. For instance, some General Ledger accounts (asset, expense) increase with a debit, whereas liability, equity, and revenue accounts increase with a credit.

Single-entry accounting is not a standardized form of accounting, but can refer to a more basic system that does not require opposing entries for every transaction. This might occur if a person simply subtracts money from a bank account to record a transaction.

Because a basic single-entry accounting system does not track and reflect the increase and decrease of every transaction, it is difficult to monitor finances and create accurate reports and balance statements. This is why Denali is a double-entry system.