A log is a score filed against a record, dated. Half stars are allowed. Everything else is built from these.
Logging a record files a score against it, with the date. That is all a log is. There is no separate step for listened and rated.
You can log an album or a single song. Both go into the same log and the same ranking.
Scores run from half a star to five, in half steps. Each star has two hit zones, a left half and a right half, and hovering shows you the score before you click.
Clicking the score you already gave clears it. That is how you un-rate something without deleting the log.
You can rate things straight away, without signing in. Those ratings are saved in your browser. If you sign in later they come with you, along with a handle, a profile and a card.
Nothing is published under your name until you have one.
Right-click any record, anywhere in the app. The menu has a Rate flyout in half stars with your current score ticked, plus Add to list, Copy link, and ways through to the artist, the album and the genre.
If the desktop app is running, whatever you play elsewhere turns up in the strip along the bottom of the window and you can rate it from there without opening anything.