[rabbitmq-discuss] memory node and disk node in cluster

[pangj]

Hello,

I saw this statement:

A node can be a RAM node or a disk node. RAM nodes keep their state only 
in memory (with the exception of the persistent contents of durable 
queues which are still stored safely on disc). Disk nodes keep state in 
memory and on disk.

So what does the "state" mean above?

Thanks.