Meditation and contemplation have nothing to do about blanking our minds, as contemporary definitions would suggest. It has everything to do with opening our hearts in receptiveness and surrender to the sway of God, and letting Him give Himself to us according to our capacity to receive Him.
Maybe the best way to make the distinction between meditiation and contemplation is to review the four phase practice of Lectio Divina, “Divine Reading”: Lectio, Meditatio, Oration, Contemplatio.
The first stage is Reading (Lectio). We read the scriptures for example, not to study, but with a receptivness to any verse that God may inspire us with. When we encounter such a verse, we pause and reflect on the verse (Meditatio), what is God saying to me? What does it mean to me? We then naturally pray (Oratio) over the verse and insight. It is natural after we have exhausted our “reflection” and “vocal prayer”, God may grant us a moment of peace and completion…we then simply sit quietly after our holy activity to rest in the Lord (Contemplatio).
Meditation, then, is what what we do, such as reflection, etc. that can result in quiet receptivity to the Lord, which is contemplation. When such contemplation is the fruit of our effort under the normal baptismal graces, it’s a lower form of contemplation known as “acquired” contemplation. The highest forms of contemplation are a pure gift of God, and is called “infused” contemplation.
I hope this helps. God bless!