History is the full record: hours logged, blocks bought, credits, corrections and retainers, newest first.
Filters
Narrow it to one kind of entry when you are answering a specific question — what was bought this quarter, what was logged last week, what got corrected and when.
Each client also has their own history, which is the one to open before a conversation about their balance.
Corrections
An entry can be corrected rather than deleted. The original stays on the record with the correction beside it.
That is deliberate. A ledger you can quietly edit is not a ledger, and the one conversation you do not want to have is the one where a client's balance changed and neither of you can reconstruct why.
What it is for
Two things, mostly. Working out where your time actually went, which is rarely where you assumed. And answering "what did I pay for?" with specifics rather than a summary.