Database links in Autonomous Database Shared are the past - Cloud links are the future
Blog: Oracle BPM
Database links have been around for decades but always require measurable administration effort. You must exchange connection and authentication information about databases to connect those, one database at a time.
With Oracle Autonomous Database Shared, the ability to connect individual databases, or even many databases, is simplified significantly. Cloud links enable you to easily make data remotely accessible for one or many other autonomous databases within your defined security realms.