A web node has 3 components.

1. A java module that maintain the connectivity to the network and does all the "ugly stuff" like encryption, message signing and so on.

2. The database (it can be mysql, oracle ...). The database stores all the blockchain data and acts as link between the java node and the web interface.

3. The web interface written in PHP. The interface uses the db to communicate with java node. It's just the frontend.

In cocnclussion masknetwork is written in java but uses php for the frontend. It's a very flexible architecture. We made tests where the web interface was hosted on a server, the db on another and the java node on yet another server.