What is a transaction?

A transaction is one movement of money: money out when you spend, money in when you are paid.

Each one names the account it moved through and the category it belongs to. Those two choices are what every other page is built on — budgets watch a category, net worth watches the balances, and reports read both.

Moving money between two accounts you own is a transfer rather than a transaction of either kind, because nothing left or entered your pocket.