Hi John,
Apply maps are used as one of the optimizing technique in qlikview scripting. As after doing mapping load the table gets deleted automatically.
It is Lookup like utility provided in qlikview.
in Join both the table gets joined based on a common criteria between two tables and it remains in memory.
So it is very important to figure out your requirement as to do a apply map or Join for joining two tables.
In apply map you need to follow certain conditions and you cant do it on any table.
