You Need to Do More Than Delete Files on an External Drive to Make Them Permanently Disappear

There’s a trick to thoroughly wiping all your data before you junk your old external solid state drive—or even computer.
MUO on MSN

This is what happens to a file when you delete it from your SSD

What this means is that the deleted file is not fully gone and can still be recovered. It's only when the data is overwritten ...
Business Insider

How to wipe a computer if you want to sell it or give it a fresh start

You can wipe your Windows PC in the Recovery section of the Settings app. To wipe a Mac, shut it down first, and during startup, use Disk Utility to erase your drive. You can also wipe a Chromebook in ...