A cloud storage is a service that let's you upload your files music,videos,documents Etc. To a server and it is stored there so it can be accessed orsaved from anywhere at any time provided your username and password.
There are a lot of free cloud services out there but the one I recommend personally is box. You can also use dropbox. But box gives 10 gb of storage for free. You can upgrade to 50gb or 100gb
And it is easy. Just create your account, visit the website or download the application . Then upload your file. So if you want to play your son‎g on your friend's phone. You can play it from your cloud storage. And if your phone is stolen or damaged and you apparently do not have a back up. You can still get your crucial files from your cloud storage. Cloud storage is secure so nobody can see your files except they know your password. 
No need to send an email to yourself to send a file from your phone to pc when you don't have a usb.you can just log in to your cloud storage and access your files anywhere,anytime
Other cloud storages are. Google cloud,one drive,just cloud,live drive,zip cloud....
Note: box and dropbox are different
More helpful posts. http://www.scamfender.com/?m=1

I will try it today. better than external hard drive

seunlayi:
I will try it today. better than external hard drive

it will cost a lot of data. But the upside. Your information will never be lost
Reply if you run into any problems