Collection-building is not simply a matter of bringing together objects which are similar in some way, but it is about organizing and looking after this group of items. There are a multitude of objects that can be collected. Aside from the beauty, rarity or monetary value of the objects, the way they are classified is what makes the collection unique.
Whether amateur or a professional, the collector must always think of how best to classify his collections. He chooses classification criteria to guide him in organizing the objects so as to best present them. The classification system is also chosen to reflect the objectives of the collector.