By default, joins are inner joins. This means that rows are included in the result set only if they satisfy the join condition.
For example, each row of the result set of the following query contains the information from one Customers row and one SalesOrders
row, satisfying the key join condition. If a particular customer has placed no orders, the condition is not satisfied and
the result set does not contain the row corresponding to that customer.
Because inner joins and key joins are the defaults, you obtain the same results as above using the FROM clause as follows: