You're both correct, but I prefer CC's answer.
The full reference starts by saying:
Books Online
A copy-only backup is a SQL Server backup that is independent of the sequence of conventional SQL Server backups. Usually, taking a backup changes the database and affects how later backups are restored. However, occasionally, it is useful to take a backup for a special purpose without affecting the overall backup and restore procedures for the database. For this purpose, copy-only backups were introduced SQL Server 2005
That is an important point, as CC emphasized.
That said, it is also true that the act of restoring a copy-only full backup is identical to a normal full backup, as far as the restore operation is concerned.
Paul
Paul White
SQLPerformance.com
SQLkiwi blog
@SQL_Kiwi