Can someone explain to me in detail a sump and a refugium?

[kyarnkid]

I want to know what these things are, I know they go at the bottom of your tank or hang off the back, but what benifits do they serve other than hiding your skimmer and heater?
Are they worth the hassle and money?
What do I need specifically to start them?
Everybody happy with theres?
Thanks

 

[fishkid1000]

Sump: A sump is a aquarium or a container that you put under your tank. Some skimmers you cannot hang of the back of your tank. It distributes heat faster if you have your heater in your sump.
Refugium:It is also a container that holds live sand, live rock, Live mud ect.ect. It provides extra biological filteration. Another + is that you can put damaged fish or corals in it.

 

[arniej]

NOt sure who posted this link but it has helped me in learning what a refugium is and how it works. Hope it helps.
http://www.geocities.com/Heartland/V.../refugium.html