A transaction in a double entry accounting system such as GnuCash is an exchange between at least 2 accounts. Thus, a single transaction must always consist of at least two parts, a "from" and a "to" account. The "from" account is passing value to the "to" account. Accountants call these parts of a transaction Ledger Entries. In GnuCash, they are called Splits.

For example, you receive a paycheck and deposit it into your savings account at the bank. The transaction that occurs is that your bank savings account (an asset) received money from your income account. Two accounts are affected, and in this case there is a net increase in your equity.

Working with transactions in GnuCash is performed using what is known as the account register. Every account you create has an account register. It will appear familiar to you as it looks very similar to the log used to track checkbooks.