Where is data stored in ELK?

Could you please clarify where exactly the data is stored in the ELK stack? I understand it's a powerful combination of Elasticsearch, Logstash, and Kibana, but I'm having trouble pinpointing where the data actually resides within this ecosystem. Is it primarily stored in Elasticsearch, or does it pass through Logstash first before being indexed in Elasticsearch? Additionally, does Kibana have any role in data storage, or is it primarily a visualization and analysis tool?