There have always been drives of sorts for the personal computer. In fact, early on, consumer grade computers didn't have internal hard drives! All work was done on floppy disks. Those days are long gone, but the age of the secondary drives has not faded.
Today, the external hard drive is the way to go for personal data backups!
To help from having to resort solely on downloading files from cloud storage, which can run into big bucks, I've purchased a Toshiba exactly like the one above. Mine is a one-terabyte unit and works quite well.
Your operating system (Windows or Apple) comes with backup/restore that you can use with your external drive.
It is HIGHLY recommended that you dedicate one (or more) of these devices to backups only! In my opinion these are not as resilient as the hard drive inside your computer.
Advantages:
These drives come in some pretty large sizes. I don't know how big they can be, but mine is a terabyte. It takes care of my internal hard drive in one sitting! If backing up personal files only, the drive will hold two backups!
They are "Plug 'n Play! USB-based.
They can be stored away from the computer in a fire-resistant safe box.
If properly cared for and handled carefully (don't drop it!) it will give you years of service.
They are great for moving files from one computer to another.
Operating systems prefer the use of these drives for backups.
In lieu of cloud storage, they can save $$$ if things go wrong with your internal hard drive.
Disadvantages:
They are more subject to wear and tear, being external, which is one reason why your internal drive is more resilient.
They are known to have a higher failure rate than internal drives.
Be careful that a computer you plug it into doesn't set it to "read-only" mode. This may not be a problem for most people, but either my own operating system is corrupted or I'm not doing something quite right with permissions. I have not yet been able to get one of my external drives out of this mode after plugging it into my brother's computer!Drop it on the floor, in water, or leave it in direct sunlight or other source of heat will destroy the drive, resulting in loss of your backup on it!
They should only be used for storage and not put into regular use like you would an internal drive. They're designed for occasional use (such as backing up files,) at least in my own opinion.
It's a good time for me to review this area also. i work as a songwriter & music producer and my operating basis for recording is to keep all audio & production files on an external drive which works more efficiently with the production software.. so in this situation i also need a back up of my external drive..
On a kinda related topic i just implemented the use of the WordPress plugin "UpdraftPlus Backup" to automatically do a full site backup to my Google Drive once a week.. it does make you sleep a little easier at night :~)