Disks fail!
It's obvious that a device containing mechanical parts rotating at speeds of up to 10,000 rpm is prone to many types of failures that can lead to data loss. And even if your Mac is equipped with a flash drive/SSD (a solid-state disk with no moving parts), be aware that it can fail because it contains electronic components such as resistors and capacitors that fail and are subject to wear and tear (the processor must read, modify, erase, and write data, and eventually even the memory cells wear out). So, your flash drive/SSD is no excuse for not backing up!
Apple renders your backups simple and automatic with Time Machine, which keeps a copy of all your files and remembers their state from previous days so you can go back in time and recover, for example, the photo you accidentally deleted. Recovering a file or folder is useful, but Time Machine can also save you in the event of theft, loss, or breakdown of your computer.
You can use Time Machine with a Mac-formatted external hard drive connected via USB, FireWire, or Thunderbolt. Do not use your Mac's startup disk to store your backups, as some customers have done!
Time Machine will keep hourly backups of the current day, daily backups of the current month, and weekly backups throughout the year. Older backups will be deleted as your backup drive fills up. At current external hard drive prices, choose one with a large capacity!
Preparing a new external drive for use with Time Machine is very simple: plug it in. Really, that's practically the only thing you have to do, as Mac OS X will detect its presence and ask if you want to use it as a Time Machine backup drive. You'll have the option to encrypt the backup drive, and if you choose this option, be sure to never forget your password!
Your first backup will take time because everything is backed up (including applications and the contents of other drives or USB sticks connected to your Mac, but not the contents of your trash). Once the first backup is completed, Time Machine will automatically back up only the files that have changed since the last backup.
To retrieve a file you accidentally deleted, choose Enter Time Machine from the Finder folder it was in, and go back in time to find the file. You can use the timeline on the right side of the screen to jump to a specific date, but if you don't remember the exact date you deleted it, use the arrow to go back in time and watch the contents of your folder change until the deleted file appears. You can navigate the disk tree from within Time Machine, so it's important to enter Time Machine from the Finder and not from another application.
To recover the old file you found, simply select it and click the Restore button at the bottom right. And if you need to recover the entire contents of a Mac, you can use Migration Assistant and choose to completely recover data and applications from a Time Machine backup.
from the article Go Back in Time by Don Mayer published on 06/19/15 in the Small Dog Electronics newsletter Kibbles & Bytes
