Maybe this is one of those things that's harder to understand if you have an accounting background. As someone without an accounting background, I found it incredibly intuitive: if money moves out of an account, that's a posting with a negative number; if money moves into an account, that's a posting with a positive number; a transaction is a set of postings that together sum to zero, indicating that no money has been created or destroyed out of thin air.

There's no need to learn any confusing "credit" or "debit" jargon, you just need to think about the movement of money (which you had to do already).