Grafana/graphite vs Icinga vs Geneos

We use Icinga(Nagios clone) and Geneos inhouse. How can I compare/relate grafana+graphite to these systems. Are they competiting or do they cover different application domains? Any opinion welcome (this is not a totally precise technical question).

Graphite: Time series database & query engine

Grafana: Time series dashboard UI & alerting rule UI & scheduling engine

thx for the info.

Does anyone have a comment regarding Icinga or Geneos compared to Graphite+Grafana? In my experience Geneos (commercial) is suitable for Realtime Monitoring, but Icinga (open source) usually has an update rhythm of several minutes. What about Graphite+Grafana?