tools – Entity web of entity interaction within the site

I'm looking for a tool that lets you create a network of entities of people and organizations (with images) that are connected to each other.
Most of all, I would like every connection to be explained as well, for example: you see that John has a connection to Peter, and when you click on the connection, it is explained that they went to school together with an old photo of them ,

Is there a tool for that matter that can be embedded in a website if users of that site can interact with that web of entities?
An open source / free tool would be nice, but if that's not available, a paid service is enough.

Thank you in advance!