table as field type??

I noticed that it's possible to have a table as a field type.
For example:
create table foo (val1 integer);
create table bar (val2 foo);
although the following doesn't work: create table bar2 (val2 foo[]);

val2 in table bar ends up as an int4, designed for storing an oid from
table foo.
Is there a way to perform a query on bar that will return values from table
foo (i.e., val1)?

Thanks,

David