Remote Procedure Call (RPC)
RPC is an acronym for Remote Procedure Call. This happens when the program delegates the execution of a piece of code to a separate server.
PHP offers xml-rpc, gRPC, Protocol Buffers also called protobuf, and Yar as different standard ways to do RPC.
<?php
$params = ['one'=>'red', 'two'=>'blue', 'three'=>'green'];
$response = xmlrpc_encode($params);
echo($response);
?>