For files and folders within SharePoint, you can share documents with others, internal or external to your organisation. Assuming you have your folders sync’d to Windows explorer, you can right click the file or folder, and you will see an option to Share.
If you are using the onlive version in a web browser, you can click the 3 dots next to a file or folder to get the Share option.
The Share options you are presented with will be the same in a browser or Windows Explorer.
In the Share window, you need to set the Link Settings. The options are as follows:
Anyone with the link – This creates an externally accessible link, and gives anyone with the link edit access to the document. This option is disabled by default, because anyone can access the link, and it is easy to lose control of who is accessing the document.
People in your organisation with the link – This is similar to above, except that the user has to be logged in, and be a part of your organisation, to restrict the access. External users will not gain access if you send this link out.
People with existing access – This creates a link but does not modify permissions. So your recipient will only be able to access the document if they already have access to the folder it lives in.
Specific People – This is the recommended option to use when sharing externally. It creates an externally accessible link, but the recipient will be required to verify their email address with a code before accessing the document. This prevents external recipients forwarding the link to other external parties.
You then have the option to Allow Editing. If you uncheck this box, the recipients will have Read Only access.
Click Apply, and then enter the recipients email address. You can then press send, which will send an invitation to the recipient. You can also click Copy Link, to paste into an existing email for example, or click Outlook to open a new email with the link prepared.
When your recipient receives the email, they will be granted access as per the settings you set in the Share settings.