Sometimes, working in a big international organization you have to perform a certain kind of work which will involve collaborating with various customers, vendors, and clients. This will definitely involve sharing your site and documents. In such a case, you will have to use features for external sharing. SharePoint Online has great features for sharing your documents and site with people outside your organization. Sharing is possible even for people who do not have subscriptions for Microsoft Office 365.
There are three efficient ways to accomplish this task:
• Your entire site can be shared by sending the invitations to external users. They will be requested to sign in to your site using the account on Microsoft.
• Your individual documents and files can be shared by sending the invitations to external users. They will be requested to sign in to your site using the account on Microsoft.
• It is also possible to send external users a so-called guest link. Following this link they wll be able to view your shared documents on the site in an anonymous way.
It is important to mention that only a single person can log in to access yur document/site with the help of sent invitation. The person whom you sent your invitation may forward it to other people who may log in to Microsoft account using their data. That is why it is desirable to enable such external sharing. The best what you can do is to set the permissions before you start sharing your documents/sites.