Historically when you need to share a document with someone, you email it to them as an attachment. SharePoint Online stores the files in a central company Document Management System and instead of emailing a copy for them to edit and send back, you can send them a link to the file so that you can co-work on the same file at the same time. There will be no more version discrepancies or lost copies. This blog will show you how you can share these document links from the various places you will work with a document within SharePoint.
1. Go to the OneDrive or SharePoint and sign in with your account.
2. Select the file or folder you want to share and then select Share.
3. Click on the arrow (>) to change with whom you want to share the document. Select Specific people under Link settings and click Apply.
By default, Allow editing is turned on. If you want people to only view your files, uncheck the check box.