Matter can be classified into crystalline and amorphous substances based on the percentage of crystalline structure present. Crystalline substances have a well-ordered arrangement of atoms, while amorphous substances lack this order. The classification reflects the degree of crystallinity, similar to how substances can be described as wet, dry, or both based on their moisture content. This analogy highlights the continuum of properties in materials, emphasizing that many substances do not fit neatly into one category but rather exist along a spectrum. Understanding this classification helps in various scientific fields, including materials science and chemistry, as it influences the physical properties and behaviors of substances.