MQTT Eventstream vs MQTT Statestream

I want to understand the difference between MQTT Eventstream and MQTT Statestream. When should I use one or another? I found somewhere on this forum that I should use MQTT Evenstream on sending HA and MQTT Statestream on receiving HA. In my test environment I configured MQTT Eventstream on sending HA, and my receiving HA receives all data without me setting up MQTT Statestream (I have MQTT broker configured).

Am I doing something wrong? Why do we need an MQTT Statestream, and what is the difference between them?