Metanet is a way of creating a graph of transactions. Beyond that, it doesn't really give you anything "out of the box", but you can use that graph to implement all sorts of things - identity, versioning, ownership and more.
The downside is that pretty much no consumer wallets make working with Metanet easy. So you either have to build you own wallet and do loads of work, or you can use www.paypresto.co which was built to make things like metanet easier.
You can also recreate the graph like na