Regular vs Swarm vs Workflow vs Graph Agents

[rmadabusiml]

I sort of understood what and when to use these type of agents but after looking at the https://github.com/strands-agents/samples/blob/main/02-samples/09-finance-assistant-swarm-agent/finance_assistant_swarm.py, I kind of lost my way of understanding Swarm.

Can someone explain difference between Swarm vs Workflow vs Graph and when to use each?
How are conversation history and memory shared between these type of agents?
Note: I went thru the documentation as well but since it uses same examples for all of these, I'm unable to understand when to use what and the above finance_assistant_swarm.py threw me off totally