All week we've stayed inside the computer. Today let's talk about the storage you can hold in your hand, the USB sticks and SD cards and little external drives, because that's where a lot of people keep their most irreplaceable stuff without realizing the risk they're taking.

They're all the same basic idea. A USB flash drive, an SD or memory card (the kind in your camera, or the slot on some laptops), and most small external drives are all storage, the filing-cabinet kind from Monday, just portable. The little ones use flash memory chips, same technology as the SSD from Wednesday. Bigger external drives sometimes still have a spinning hard drive inside. Either way they hold your files with the power off, which is exactly why they're so handy for moving things around or clearing space.

Here's the part people miss, and it's the reason I'm writing this one. Portable drives are convenient, not permanent. They fail more than folks expect. USB sticks and cheap cards wear out, and some are outright fakes that lie about how much they hold. They're tiny, so they get lost, left in a laptop, or run through the wash. And a single drive is one drop or one theft away from taking your files with it.

So here's the rule I want you to remember. If the only copy of a photo or a tax file or an important document lives on one USB stick, you don't have a backup. You have a coin flip. A copy in one place isn't a backup. A backup means the same file lives in two places, so losing one is an annoyance instead of a catastrophe. Use portable drives to carry files around, not to be their only home.

And that's the whole picture, from the RAM inside your machine to the stick on your keychain. Get the model straight and you'll never overpay for the wrong upgrade, or lose something that actually mattered to you.

Got important files sitting on a single drive and want a real backup you don't have to think about? Book a remote session and I'll help you set one up.