It only takes a few minutes of watching the orientation video from Google about their newly released Google Drive to see the obvious similarities with other Cloud storage/file sharing programs such as Dropbox.com. Both programs, and other similar types of programs, work through a desktop folders that automatically synchronizes with a matching folder on the provider's server. So, both Google Drive and Dropbox have a way to put a file folder on your computer and any document or file you drag to that folder will be automatically loaded into a virtual folder online. The virtual folder can be used to synchronize any number similar folders on other devices, such as smartphones, tablets and other computers.
For example. I download a photo from my camera to my laptop computer and then copy the photo into my Google Drive or Dropbox folder. I can then go almost instantly to my desktop computer, open the corresponding Dropbox or Google Drive file folder and there is the copy of the photo waiting for me to use. The same photo is also available on my iPad or my iPhone if I am using Dropbox, but at the time of its introduction, Google Drive is still not yet available for Apple's iOS devices. But it is being advertised as available soon.
All of the documents in my folder belong to me and are not available or open to the general public. If I choose to share a document (photo, audio file etc.) I invite someone to share the file. Once they accept the file sharing invitation, they have to have Dropbox or Google Drive to transfer the file, but they will also need the corresponding application program running on their computer. As soon as the remote user gets the invitation, they can look at, copy, improve or do anything they like with the shared file. They cannot see or do anything with the files that are not shared specifically with them or shared publicly.
On a more mundane level, Google Drive offer 5 GB of free storage with paid-for options up to 1 TB. Dropbox has 2 GB free and paid options up to 100 GB. Microsoft offers 7 GB of free capacity with its SkyDrive and Apple's iCloud offers 5 GB. I have noticed that some of the storage capacities are somewhat of an illusion. For example, Apple's iCloud can be used to synchronize email, calendars and many other functions of your iPhone, but the 5 GB of space is very easily used up. On the other hand, I have seldom used even half of the 2 GB+ of space I have in my Dropbox folder.
Not too coincidentally, Microsoft announced changes to its SkyDrive online storage program. This would have been bigger news than it was except for file size limitation of 2 GBs and the fact that the program was previously 25 GB free, now cut down to 7 GB. Both Microsoft and Google are charging less for their paid storage options than Dropbox. Apple's iCloud is also presently more expensive than either Microsoft or Google, but less expensive than Dropbox.
How many of these services do you actually need? Dropbox has made a huge difference in the way I work with files. I no longer need to remember to take my flashdrive with me to presentations or for doing research, I can just drop the files into a convenient Dropbox folder and they are automatically on my various computers. I find myself using this to move files from computer to computer inside my home not just at distance. The larger file sizes has also been a boon to moving images and large documents across the world. I no longer have to worry about my recipient's email file size limit. I can just send whatever file I need to without worrying about the size.
With more options, it is likely that this type of service will become even more pervasive and will continue to affect the way we use and interact with computers in the future.