What does the (+) operator mean in a where-clause of PL/SQL?

Question

I have a SQL query something like:-

Select Table1.attr1, Table1.attr2, Table2.attr3, Table2.attr4
From Tab1 Tabel1, Tab2 Tabel2
Where Tabel1.Attr = Tabel2.Attr (+)

So what does the above mean? Is this a right outer join?

Answer 1

Yes, it means right join. if the statement was like .... where Tabel1.Attr (+) = Tabel2.Attr, it have to be left join.