Kapacitor email alert trigger DBout and HTTPout

InfluxDB 1 Kapacitor
1

I configured basic email alert via chronograf.
The script contains dbout and http trigger as well .
Why is that ?

var data = stream
|from()
.database(db)
.retentionPolicy(rp)
.measurement(measurement)
.groupBy(groupBy)
.where(whereFilter)
|eval(lambda: “usage_system”)
.as(‘value’)

var trigger = data
|alert()
.crit(lambda: “value” < crit)
.stateChangesOnly()
.message(message)
.id(idVar)
.idTag(idTag)
.levelTag(levelTag)
.messageField(messageField)
.durationField(durationField)
.details(details)
.email(‘haiat_m@mail.tel-aviv.gov.il’)

> trigger
> |influxDBOut()
> .create()
> .database(outputDB)
> .retentionPolicy(outputRP)
> .measurement(outputMeasurement)
> .tag(‘alertName’, name)
> .tag(‘triggerType’, triggerType)
**> **
> trigger
> |httpOut(‘output’)

2

InfluxDBOut is configured so chronograph can have the alert history.
I am not sure what ism se case for httpout.