Bitcoind provides a direct interface to the bitcoin network and it also exposes a `JSON-RPC` API. This class allows to connect to a local instance of a bitcoind server and make simple or batch RPC calls to it.
First you will need a running instance of bitcoind, setting up a username and password to connect with it. For more information about running bitcoind please refer to the [official documentation](https://en.bitcoin.it/wiki/Running_Bitcoin).