The httpServerResponse.connection is an inbuilt application programming interface of class Server Response within http module which is used to get the response socket of this HTTP connection.
Syntax:
response.connection
Parameters: This method does not accept any argument as a parameter.
Return Value: This method returns the response socket of this HTTP connection.
Example 1: Filename: index.js
// Node.js program to demonstrate the
// response.connection APi
// Importing http module
const http = require('http');
// Setting up PORT
const PORT = process.env.PORT || 3000;
// Creating http Server
var httpServer = http.createServer(
function (request, response) {
// Getting connection
// by using response.connection Api
const value = response.connection;
// Display result
response.end("port address : "
+ value.address().port, 'utf8', () => {
console.log("displaying the result...");
// Closing the server
httpServer.close(() => {
console.log("server is closed")
})
});
});
// Listening to http Server
httpServer.listen(PORT, () => {
console.log("Server is running at port 3000...");
});
Steps to run:
node index.js
Console Output:
Server is running at port 3000... displaying the result... displaying the result... server is closed server is closed
Browser Output: Paste the localhost address http://localhost:3000/ in the search bar of the browser. 
Example 2: Filename: index.js
// Node.js program to demonstrate the
// response.connection APi
// Importing http module
const http = require('http');
// Request and response handler
const http2Handlers = (request, response) => {
// Getting connection
// by using response.connection Api
const value = response.connection;
// Display result
response.end("family : "
+ value.address().family, 'utf8', () => {
console.log("displaying the result...");
// Closing the server
httpServer.close(() => {
console.log("server is closed")
})
});
};
// Creating http Server and listing
// on the port 3000
const httpServer = http.createServer(
http2Handlers).listen(3000, () => {
console.log("Server is running at port 3000...");
});
Steps to run:
node index.js
Console Output:
Server is running at port 3000... displaying the result... displaying the result... server is closed server is closed
Browser Output: Paste the localhost address http://localhost:3000/ in the search bar of the browser. 
Reference: https://nodejs.org/dist/latest-v12.x/docs/api/http.html#http_response_connection