Hard disks drives are know for just failing. Even office servers with copies over multiple drives can go. It even happened once to my office so I do know the problems this might cause. Even if your notebook computer has SSD storage instead of a hard drive you can find the computer go dead.
So backing up is really a necessity.
You can backup to a cloud drive like Dropbox or Microsofts newly renamed One Drive. But nothing really beats having someway physical you can get at.
These days portable storage is much larger and quicker. I would recommend getting two of these drives. Each week or each month you back up alternately to one of these drives. Making sure you keep on of them with someone else. These drive are also password protected which also helps with security!
Western Digital is in my opinion currently the most reliable make. These are 1TB is size which is currently the best cost effective version for a portable drive. If you follow my advice and you buy two I suggest you choose different colours which will help identify each and assist with the rotation process.
At the time of writing these drives are £55 each from Amazon UK. A saving of £10 over one high street store we checked.
Hard Black Carrying Case for Portable Drives
To keep things neat and avoiding damage this case is a good idea. It is a durable faux-leather protector for your portable Western Digital hard drive. The soft-lined case features an inner mesh compartment for one USB cable and accessories.
Dimensions (L x W): 5.25 x 4.125 ” (132 x 105 mm)
On Amazon UK the price is £5.99.