Obsidian vs Rome - What's the Difference?

i've been trying to solve a problem for years, iis just keeping track of work. And in context a the legal stuff i do, there's lots of phone calls and contact made with people. Some of the stuff i work on as a lawyer takes years to come to fruition. Having the stuff written down and thinking it through, when you're under fire, it actually makes a difference. I can look at now the page for that created through obsidian or slash rome, and then look back historically to see who i talk to when i talk to them,. i can create links to the emales that i sent related to it. All this stuff is safe with obsidian because