They are just written over. I don't remember the terminology but I'll try to explain. Imagine that someplace on your disk is an old fashioned paper phone book and in that phone book is a list of phone numbers and addresses. Somewhere on your disk is a "phone book" with a list your files and their addresses, where they are located on the disk. When you format a disk what happens is the "phone book" with the list of files and where they are is erased. The files are still there. They only go away when you overwrite them. So if you accidentally format a disk, whatever you don't, don't use it anymore. Lock it so nothing can accidentally be written to it then get the software mentioned above or take it to a data recovery service.

Made an appointment at the local Apple “Genius Bar” today for a battery replacement in my IPad. Since they never answer their phone, calls go directly to an Apple support assistant - mine was a very nice guy. We discussed the battery replacement at length including backing up the IPad (which I do to ICloud automatically), disabling “find my IPad”. Etc. He looked up my IPad by S/N and confirmed the price, which amazingly (for Apple service) was reasonable. Drove to the mall, walked half a mile to the Apple “Genius Bar”, exposed myself (even though masked) to 50-100 people inside during a period when N.C. is experiencing 7,000 new Covid cases per day. The nice tech repeated everything and then said they didn’t have a replacement in stock (they don’t change the battery, they replace the IPad). After more checking and another 20-30 minutes, turns out no replacements are available (NLA), so I am SOL. But, they would give me $65 as a trade in on a new IPad. OK, I’m in, BUT no new IPAds in stock (at an Apple store in a major city). The net-net is 2 hours wasted and no fix. i’ll either buy a new one from Best Buy or replace the battery myself (I have actually repaired a previous IPad).

So what’s the point to this rant? These “geniuses” at the “Genius Bar” and the support line and no less than 4 support personnel I interacted with, given the model, S/N and age couldn’t figure out that that a replacement wasn’t possible, and that no new ones were in stock locally, and don’t answer their store local phone. These don’t seem like geniuses to me.

And I will say this. The product has performed fairly well over it’s lifetime, although getting slower and slower with each OS update and age. The design is poor in that the battery should be accessible and replaceable by the user (could this be designed to insure you will toss the product and buy a new one periodically?), and the support program needs some work if they can’t tell that repairs/replacements aren’t possible in real-time without a 2 hour store visit. Nope, no geniuses here.

End of rant...

Yea, I've been receiving a lot of them lately.
Checking the header info, mostly from Eastern Europe.
Half for an anti-virus program that I do not use.

If you can't check the header, ALWAYS check the from/return address! It's NOT the AV company!
NEVER click on anything in the email - Always go to the known URL for the company you use.
Aside from the fact that I know when my subscription expires, is on auto-renew, and I know that it is current,
THAT's my first indication that it is a scam.