Usually, each of the users sends a HTTP request for the page. The server receives the requests and delegates them to different workers (processes or threads).
Depending on the URL given, the server reads a file and sends it back to the user. If the file is a dynamic file such as a PHP file, the file is executed before it's send back to the user. Once the requested file has been sent back, the server usually closes the connection after a few seconds.
Mealen;
"Neden müşteri hizmetlerini aradığınız zaman bekletiliyorsunuz?" sorusunun "Tüm müşteri hizmetleri çalışanları şuan diğer müşterilerimizle ilgileniyor." cevabına benzer bir cevabı var hocam.