Replays (save files)

Replays are the mod's save files listed under the Host tab in the Multiplayer screen.

Under the hood they function as simple zip archives. They are located in the MpReplays folder next to RimWorld's saves folder.
On Windows: Press Win+R, type appdata, go to LocalLow\Ludeon Studios\RimWorld by Ludeon Studios\MpReplays.

Replays can be watched to recap a game and servers can be hosted from them.

During autosaving, they are saved only on the host's computer, but there's a Save replay button in the ESC menu which allows saving locally.

The option to convert a replay to singleplayer appears in the ESC menu during watching.