Jass - Saving unit groups as handle

[Saito]

Hey there!
I'm looking for syntax of saving and reading unit groups as hashtables in jass, for it can't be done through gui.
I'd be also glad if one could tell me difference between unitpool and unitgroup.

 

[TriggerHappy]

Unit Pools

http://wiki.thehelper.net/wc3/jass/common.j

call SaveGroupHandle(udg_Table, 0, 0, udg_Group)
set udg_Group = LoadGroupHandle(udg_Table, 0, 0)