Bowen's Reaction Series is a concept in geology that explains how different types of minerals crystallize from molten rock, or magma, as it cools. The series is divided into two branches: the discontinuous series, which includes minerals like olivine and pyroxene, and the continuous series, which features minerals like plagioclase feldspar. Each mineral forms at specific temperatures, influencing the composition of igneous rocks. As magma cools, the minerals that crystallize first are typically rich in iron and magnesium, while those that crystallize later are richer in silica. This process helps geologists understand the formation of igneous rocks and the conditions under which they develop.