I have been using and evaluating the free cloud storage and sharing services from the major operators. Individual pros and cons continue to evolve, while they copy or adapt each others features. I have decided to share files on 3 major cloud drives, (Dropbox, Google and Microsoft) as although some can now be used without an account, they are much easier to use if you do have one. At the moment there appears to be no practical way to share and update files on iCloud Drive.
Google lets you store up to 15 GB free, which includes Gmail storage. Google Docs, Sheets etc. don't count towards your limit.
With its desktop app, your computer's Google Drive folder syncs with the cloud, making it easy to update.
You can set folders as
I now put all images that I use in Google Sites in Google Drive, to save duplication and facilitate changes during site development.
Also shared audio and music files, especially if they need updating frequently.
And some photos used in online presentations and slideshows. (See Photos).
Microsoft's alternative to Google Drive works in a similar way, with desktop sync and similar sharing settings. Their free 5 GB limit can be increased with Office 365 and photo backup. (See Photos)
Microsoft Office docs can be viewed on line in their Web Apps or up- and down-loaded in their original format. (See Office)
And now you can stream individual music tracks as well as downloading music files or folders.
But OneDrive seems to synchronise more slowly than its competitors, and I have drastically reduced what I store there, to try to speed things up.
Starts you out with 2 GB storage free, but you can 'earn' over 20 GB more.
Desktop folder syncs with the cloud.
It's unique benefit is enabling automatic sync of favourites on mobiles, great for frequently updated files.
You can now also share a link to a file or folder on Dropbox. Unfortunately it makes it look like you have to join when you click on the link, which puts off some people.
Now has tighter links with MS Word (free app for tablets and phones), and does not work as happily with DocsToGo, previously my preferred mobile docs app.
I must not forget Apple's offering, up to 5 GB free for synchronising between mobiles and desktop via their cloud.
Great if you use an iPod, iPhone or iPad for your photos, and you're happy for Apple to organise your photos within their database. At least you can export individual or selected photos either as modified in Photos or in their original form.