Note that you never went into the restaurant (server). For security purposes the owner of the restaurant does not allow anyone inside because there are a lot of bad people that might try to steal or break things.
The Restaurant Manger (Control Panel) is an administrator. He makes sure that everyone is acting the way they are suppose to. The Chef (PHP) is filling the orders that the order taker asks for. The order taker is only filling order that are on the menu. The refrigerator stays stocked with all the right ingredients and we have all the right seasonings so the food tastes good.