To understand how remote file access works, let's run through a typical experience.
Your service will install a file folder on your computer or device. Any file you drag or copy into that folder is duplicated -- using a secure sockets layer (SSL) and, in some cases, encryption -- onto a server somewhere on the Internet, much in the same way shared documents are stored on an office network. Meanwhile, a background service on your computer or device periodically syncs each of the folder's contents with its duplicate on the Internet server. Thus, any changes you make on one version of the file will be reflected in all versions.
Although once distinct concepts, the line separating "remote file access" from "cloud computing" grows increasingly blurred, both in terms of the services they provide and the way companies market them. We use the term remote file access throughout this article, but the services we describe overlap the two categories somewhat.
Most services allow you to access your remote file folder from devices such as tablets and smartphones. Simply install the necessary app and you're ready to go. In many cases, an additional option to share your photos, videos or other files on the remote file service then appears on your app menus. For example, a Google Drive user with an Android phone who takes a picture will see a Google Drive option on the sharing menu, next to Picasa, Twitter, Facebook and so on. Like your desktop computer, these devices will sync every so often with the file servers, much as they periodically check for new e-mails or texts.
Once your files are on a remote access server, you can share them publicly or with specific people. Implementations vary, but typically a settings menu lets you specify who can see a particular document, which can vary from anyone on the Web, to anyone who has the link, to only specified people. Many services require users to register and make an account (typically free) before they can access the file. You can also specify permissions controlling what viewers or collaborators are allowed to do with the file (like read only, edit).
Some services, like Google Drive and Microsoft SkyDrive, also enable you to create documents online. These are stored on the server, but you can also download them to your computer or device to work on them while offline. The system will sync them with the remote file service once you re-establish Web access.
Remote file access and cloud servers provide powerful tools and convenient file access, but they also introduce security vulnerabilities. These cut two ways: On the one hand, hackers can and will exploit security holes in the servers and on devices that access them; on the other, many users will rankle at security solutions proposed to stop those hackers, particularly digital rights management (DRM). Keep such concerns in mind when choosing a remote file access service -- or deciding if one is right for you in the first place [source: Thomas].