Yes, dynamis is basically this:
You appear in the zone at the mog house of either Bastok Mines, Windy Waters, South Sandy, Ru'Luade Gardens(Jueno)(sp), Beaucidine(sp) and Xarcarbard(sp). You kill the mobs in usually a specific order, because some mobs have a time extension, which you need to be able to have enough time to get to the Mega Boss. Once the Mega Boss is killed you can obtain a key item. You need the key items from Jeuno, Windy, Sandy, and Bastok to be able to go to the Beaucidine, then you need Beaucidine's to go to Xacarbard.
The Cities are empty of the NPCs and everywhere are these statue mob things. Once a statue mob is hit, it spawns like 3 mobs. Sandy has orcs, windy yagudo, etc u get the picture. Relic equipment is the rare drops off those, which are all rare/ex and really the reason for going to dynamis.
Max of 64 people in zone. My ls usually takes like 40 at most. We hate large groups.
Good readings on dynamis and relic gear can be found here:
http://mysterytour.web.infoseek.co.jp/ffxi/us/