Changing your mind
Every save keeps what it replaced. Nothing you write is ever really lost.
Every time you save, Inkling quietly keeps a copy of what the entry looked like before that save. Those copies are its history, and you can go back to any of them.
Open an entry and look for its history in the editor. You can read an old version before deciding, rather than restoring blind and hoping.
Restoring is itself a save
This is the part worth understanding, because it makes the whole feature safe to use: when you restore an old version, that restore is recorded as a new save. Which means the version you just replaced is also kept.
In plain terms — you can undo the undo. There is no way to lose work by exploring your own history, so explore it freely.