Backlinks answer the question “what links here?”. While you read a note, the backlinks pane in the right sidebar lists every other note that links to it. It is the reverse of the wikilinks you write.
The backlinks pane
The pane is headed Linked from N, where N is the number of notes that link to the one you’re reading. Each row is a linking note, with a count of how many times it links here. Click a row to jump to that note. When nothing links to the current note, the pane reads No backlinks yet.
The list refreshes as you work: add a link in another note and this note’s backlinks update to match.
What it shows
Each row names the source note; it does not show a snippet of where the link sits. As in search, results never decrypt your notes just to preview them. A note linking to itself is not listed, since a backlink is always from another note. Links from notes in the Trash don’t count, because trashed notes are set aside.
Limits
Backlinks follow resolved wikilinks only: a link to a note that doesn’t exist yet creates no backlink (see Wikilinks). Backlinks are within the current vault.