Guides
Guides
Plain-language explainers on Mac backup, NAS setup, and iCloud storage — no vendor pitch, just how the pieces actually work.
Updated August 9, 2026.
Each guide below stands on its own — pick the one that answers the question you actually have. ThirdCopy gets a natural mention where it's relevant, but these aren't ads: they're the explanations we'd want if we were the ones searching.
Backup concepts
Mirror vs. sync vs. clone
Three words people use interchangeably for backup software that actually mean very different things — and why the difference matters for what you can recover.
The 3-2-1 backup rule for Mac users
The classic backup rule, translated into an actual Mac + NAS + cloud setup you can build this weekend.
NAS backup
Does Time Machine work with a NAS?
Yes, with real caveats — AFP is being phased out, SMB is required, and 2026 has had a rocky patch. Here's the current state.
Back up a Mac to a Synology NAS
Setting up reliable, automatic backups from your Mac to a Synology NAS, step by step.
Back up a Mac to a QNAP NAS
The QNAP-specific setup steps and gotchas for automatic Mac backups.
Back up a Mac to a UGREEN NAS
UGREEN's NAS line is newer to the market — here's what Mac users need to know to back up to one.
iCloud and external drives
iCloud "Optimize Mac Storage" and your backups
What actually happens when a backup tool tries to copy a file iCloud has evicted from your disk — and why it matters.
Automatically back up an external drive on Mac
Getting a truly hands-off, scheduled backup to an external drive, without remembering to plug in and click a button.
Looking for a vendor comparison instead?
If you already know what you want to do and just need to weigh specific tools against each other, Compare covers ThirdCopy against ChronoSync, Carbon Copy Cloner, SuperDuper!, GoodSync, FreeFileSync, Time Machine, and Arq, feature by feature — including the places where they beat ThirdCopy outright.
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