How to make a term synced on all nodes?

[HP Wei]

Let's say I have an ets table (or some other term (object) in erlang)
I want to keep a copy of it on all active nodes.
Each of these nodes will update some part of this table.
After an update, I want all copies on different nodes to be synced.

(The purpose of keeping a copy on all nodes is to keep the info
 in this table alive all the time even when some nodes go down.)
 
I figure that this is what people in the Erlang world are doing 
with ease all the time.  
However, as a beginner, I want to get some references (or example,
fragment of codes) as to how to this.
(1) how to make this table globally visible, (a name refering to 
    one copy of this table)
(2) how to keep it synced.

Thanks,
HP