Although SETS are the defined method of creating a relationship between tables, I've found that mapped tables do essentially the same thing.

I've read that mapped tables create a 1-to-1 relationship but I am not seeing that when the many side of the table is the first in the mapped table definition.

Can someone tell me what the difference is between these and how each is intended to be used? I find mapped tables to be the easier of the two for reporting purposes.