CloudKit references — is this a forward reference or a back reference?

I'm trying to understand the terminology around forward vs backward references in CloudKit.

Say I have two record types:

• User
• LeaderboardScore (a score belongs to a user)

The score record stores a user reference:

score["user"] = CKRecord.Reference(
    recordID: userRecordID,
    action: .deleteSelf
)

So:

• LeaderboardScore → User
• The user record does not store any references to scores

From a data-model perspective:

• Is this considered a forward reference (child → parent)?
• Or a back reference, since the score is "pointing back" to its owner?

My use case is having leaderboard in my app and so i have created a user table to store all the users and a score table for saving the scores of each user of the app.