Of course we all know apai, because fire is no stranger to our lives, because fire is a set of program instructions and protocols used to build software applications. Fire acts as a messenger that receives user requests and tells the system what to do, then responds appropriately to the request. As an analogy, in the restaurant suppose the customer is the application user and the kitchen is the system. The kitchen will prepare an order or customer request, in this analogy, fire is a waiter who communicates customer orders to the kitchen or system and brings back food and drinks on demand.