That command will build a JSON API avaiable on the 1808218082
port. You can check if that works by typing http://127.0.0.1:18082/json_rpchttp://127.0.0.1:18082/json_rpc
in your browser.
In this way, you created the instance of Monero PHP library. All the calls are in details on https://getmonero.org/resources/developer-guides/wallet-rpc.htmlthis page page.