Normal Minecraft death mechanics do not apply to our server. Upon death, what happens depends on the area.
The normal, or default, death mechanic is for your items to go to the Graveyard. This is a special area on the server, which amoung other things, features a number of graves. Upon death, the your items go into a randomly assigned grave.
Upon respawn, you can then go search the graveyard for your grave, or find it via a Phantom Potion. All graves are marked with a headstone (sign) containing the deceast player's display name, and the date of their death. You can read more about graveyard headstones here.
You can optionally use a Gem of Life to bypass the grave system, and instead respawn with all of your items in your inventory, in your usual respawn point. Gems of Life will be consumed upon use (death) -- one gem per death.
If a you without a Gem of Life, you can easily return to your grave, without searching for it, by drinking a Phantom Potion.
Drinking a Phantom Potion will teleport you to your most recent grave. It will also act as a Gem of Darkness, and make you invisible to any hostile mobs present in the graveyard, for 30 seconds.
The Potion of Restitution is similar to the Phantom Potion, however, it serves a different purpose. Rather than teleporting you to your most recent grave, a Potion of Restitution will teleport you back to where you most recently died.
This can be useful in situations where you were exploring and do not want to trek all the way back to where you were slain by that pesky enderman -- or when you don't know where you were exactly where you died, but it seemed like an awesome place to build your next mansion.
IMPORTANT: The Potion of Restitution is completely unrelated to your items -- as your items will be in a grave, not where you died. DO NOT use the Potion of Restiution if simply trying to get your stuff back.
All bosses and dungeons you'll encounter on the server will either not allow you to fight them with items, or allow you to keep all items in your inventory upon death for free.
All PvP arenas will protect your items on death for free.
All minigames will either give you an alternative inventory, prevent you from taking items in, or protect your items on death for free.