Sales that select both Product Types and Specific Products in the Conditions
A blank selection of products or product types will match all products.

Both 'product type' and 'product' conditions need to match for the sale to match the product.

If you selected product type A and a single product from product type B in your conditions, then the sale would not apply to the single product from type B even if added to the cart.

Therefore the condition could be thought of as an AND, meaning that all conditions need to match for the sale to apply.

Let me know if you need further clarification.