Can someone explain "Cloud Storage"
I'm not the expert, but I'll comment (since I have an opinion to share).
As I understand it, there are many "clouds" (servers) and the prices vary. Some give you a nominal amount of storage for free, maybe 2GB or so, and then charge for more. I believe you can arrange to use any one you choose and there are some big names (Google, Microsoft, etc) which offer cloud storage.
I see the advantages mostly for those who want to access their files from several devices at different times and places. Everything you've put in the cloud will be available. It's also considered to be a good way to back up files. Speed of access should be no different from your internet connection. In some cases, the cloud may offer some software for you to use. Note that some computers may have a setup option that pre-empts storage of your files on your own hard disk in favor of cloud storage.
On the other hand, I don't think it's too different from the hosting sites that have existed for 15 years or more for storing your photos. My experience in that regard has not been too good. I've been "dumped" by 2 different hosting sites, one of which went out of business with no notice. The other gave a few months' notice to remove your files. Fortunately, I wasn't depending on online storage alone.
One shortcoming is that you may not have easy access to the cloud if you are working remotely and there have been one or two outages that kept people from their files for a day or so.