Backup is a very necessary thing as a blogger if you wish to store, save and share information from one device to another like a phone, a computer, a laptop, iPad or iPhone. All Mac devices have back up facility. I use an iPhone 7 as my primary phone and a MacBook Air as my first choice of computer. It is thus imperative that I take backups of my information both on the Mac and iPhone on the iCloud. An iCloud is a data storage device that can store information such as videos, contacts and photos. You can buy space on the iCloud like 10 GB, 50 GB etc. for a price from Apple and then take back up on it. This is useful even if you lose data due to a crash or lose your device. You can be sure that your data is available to you all the time and that too on the go. There is no need to carry cumbersome hard drives or disks with you in your bags to save data. The iCloud feature saves that problem.
Google also gives you that facility as a Google Drive and Photos where you can save data or pictures and share them with a third party. I share data with my service provider on Google Drive in this manner. This too can be purchased at a cost. Technology today has bridged that gap. Even your music and movies can be shared and stored in this manner.
At all time, take back up. It is your only safeguard against a crash. iCloud is a storage subscription service. When you subscribe to iCloud, you get 5 GB of space free and you cannot exceed the capacity of 15 GB of storage space.
iCloud Shortcoming: iCloud is not a Dropbox and does not have that kind of a facility. Application updates are not automatic. 5 GB is too little space and you may need more of it. But all in all, it is the best back up service as it is in the market along with Dropbox and certainly a popular one.