I'm trying to understand the differences and commonalities among various systems enabling electronic contracts (building it here
What I can't figure out: what exactly is an "Ethereum Address"? How do I address an Agent in Ethereum and how do I check that the address obviously belongs to the addressee?
Related: what's a realistic frequency for transactions for Ethereum Agents? Range is enough: more like one-per-second (interactive) or ten minutes per transaction (batch and come back later)?