Prudent journals are a combination of both a daily (most often personal but not necessarily so) journal that some of us keep to record things (activities, ideas, thoughts) regularly AND a journal for transactions in the accounting or book keeping sense (this is probably the more important part).
Don't let accounting and book keeping put you off because that's what Prudent help you with. You're not expected to create any accounts or manually enter any transactions at all (coming soon)!
Also, the journal of activities, ideas and thoughts part is also COMPLETELY optional. It is there if it is useful. Otherwise, Prudent already gives you insightful views into your finances that are derived from your transactions alone.
The journal that Prudent understands is in the Ledger format. The following example shows you the syntax of a typical journal:
2018/01/01 *Opening Assets:Savings $30000 Assets:Property:MiCasa $180000 Equity P 2018/01/02 15:50:00 USD $1.36 P 2018/01/02 16:23:00 BTC $10800 P 2018/01/02 17:35:00 🐑 $1080 2018/01/03 Assets:Farm 2🐑 Assets:Savings
Check out the getting started section of this documentation to learn more about journal syntax or download a sample journal that has a range of examples from starting a journal to buying stocks to commenting.
Remember that this journal is there for your convenient editing. You don't have to manually enter any of these transactions yourself and can rely on convenient add-ons (coming soon) or external tools that does it for you. With text files, it's easy!