Both SharePoint Online and OneDrive for Business include a Share feature that allows you to share documents and files with other people.
Why would you want to do this?
Let's say you're working on a new ad campaign for an upcoming product release. Sharing the project files allows everyone you're collaborating with to read and edit the same version of the files, thus eliminating the need for email attachments and the hassle of juggling multiple review copies.
The people you share with can be employees inside the company or customers and partners (also called external users) outside the company. You share files either by requiring a username and password (this is known as authentication) or by providing an anonymous guest link. Only those guests who have the link will be able to access the shared files.
How are shared files secured?
Typically, when you go from one website to another, the originating URL is captured so the new website can see where traffic is coming from. This "referer" data is used for search engine optimization, content optimization, audience targeting, and so on. When a user opens a file shared through SharePoint Online or OneDrive for Business and then browses to another website, the URL of the shared document is not included with the referer data. This prevents the inadvertent disclosure of the shared document URL, regardless of how the document is shared.
To further protect against accidental disclosure of the shared document URL, SharePoint Online and OneDrive for Business use the “noindex” value in the page's meta tag. This value tells compliant search engines to not index the URL, which will prevent the shared document from being included in search results. This only applies to those search engines that observe the noindex tag.
Want to know more about sharing files?
If you're looking for instructions on how to share a file, see:
If you're looking for instructions on how to set up and manage sharing for your Office 365 subscription, see:
Manage sharing with external users (for Office 365 Small Business subscribers)