What are proxies and what are they for?

Question

PHP

In Symphony 4 and Laravel 5, these are the parameters that appeared. Symphony has them in Request, in Laravel they go to Middleware

class TrustProxies extends Middleware
{
    /**
     * The trusted proxies for this application.
     *
     * @var array
     */
    protected $proxies;

    /**
     * The current proxy header mappings.
     *
     * @var array
     */
    protected $headers = [
        Request::HEADER_FORWARDED => 'FORWARDED',
        Request::HEADER_X_FORWARDED_FOR => 'X_FORWARDED_FOR',
        Request::HEADER_X_FORWARDED_HOST => 'X_FORWARDED_HOST',
        Request::HEADER_X_FORWARDED_PORT => 'X_FORWARDED_PORT',
        Request::HEADER_X_FORWARDED_PROTO => 'X_FORWARDED_PROTO',
    ];
}

What is it and why?

Answer 1

https://github.com/laravel/laravel/blob/master/com...