# What goes into a stream module?

1. Event definition(s)

   event LotteryCreated(lotteryName:String,amount:Int)
   

2. Event-data definition(s)

   event-data Address(line1:String, city:String, state:String, pinCode:String)
   

3. Event-tag definitions(s)

   event-tag SystemGenerated
   event-tag UserGenerated
   

4. You can also mark some events as past-events

   past-events ("OldEvent", "UnusedEvent")