Not only safer,
Especially if these CDs are the only copies of the files you have.
We always say, Backup, Backup, Backup. That's backup 3 times so you have the originals and 3 copies, all on different media, (backing up 3 times onto the same hard drive is not backing up 3 times).
So you're right to ask and you are right to backup. CDs generally last longer than hard drives but even so they might become corrupted or unreadable, so having 3 backups preserves your photos. If one copy fails, you still have 3 others with which to make yet another backup.
Nowadays we have much more choice in what we backup to, like external hard drives, DVD, memory sticks, and so on, so it is now a relatively easy process.
Does that help?
I'm not sure why you posted this in the Avast anti-virus forum though...