There are numerous varieties of basil and in this country the most commonly used basil is referred to as “sweet basil” which is typically grown in Mediterranean countries. Sweet basil is the type found in Italian dishes, is most commonly used fresh and typically is added towards the end of the cooking process, as cooking quickly dissipates the herb's distinctive flavor.
When dried, basil has better flavor. The drying process forces the collapse of the plant tissue, and brings about more essential oils in the herb. The increased oils also increase the ease of which food around the herb can absorb its flavors.
If your recipe calls for one tablespoon of fresh basil, you can replace that with one teaspoon of dried basil.