if i erase my iphone is everything automatically saved

Hey there arionna553,

The short answer to your question is no, a backup isn't automatically made when you decide to erase a device, even though it's always recommended to make one just in case. That being said, we also see your post is regarding iCloud, and we'd like to help by offering a few things for your to check if you've already erased your iPhone:

1. You can log into the iCloud website to view data that has synced to iCloud from your iPhone prior to erasing it: iCloud To sync the information back to your iPhone, you'd need to set it up, then sign into iCloud.
2. If you have a recent backup in either iCloud, or on your computer, you can restore your iPhone from that backup using these steps: Restore your iPhone, iPad, or iPod touch from a backup This link will help you locate backups: Locate backups of your iPhone, iPad, and iPod touch
3. If your iPhone isn't erased yet, and you haven't yet made a backup, you can make one using these steps: Back up iPhone

Cheers.