Skimming is the act of reading something very quickly and taking notes of important topics and when you're scanning, you're actually reading with one specific goal in mind, as in, you already know what you're looking for and you're reading in order to find it, only. So when you're looking for the connection between different points and topics and how they relate and compliment each other, you might want to try close reading, which is "the careful, sustained interpretation of a brief passage of a text".