What is the standard SQL Query to retrieve the intersection of tables?

Question

Selecting the union:

select * from table1 
union 
select * from table1_backup 

What is the query to select the intersection?

Answer 1

inner join i think: suppose T1 and T2 have the same structure:

select T1.* from T1 inner join T2 on T1.pkField = T2.pkField